Electrocatalyst

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A platinum cathode electrocatalyst's stability being measured by chemist Xiaoping Wang Electrocatalyst ANL.jpg
A platinum cathode electrocatalyst's stability being measured by chemist Xiaoping Wang

An electrocatalyst is a catalyst that participates in electrochemical reactions. Electrocatalysts are a specific form of catalysts that function at electrode surfaces or, most commonly, may be the electrode surface itself. An electrocatalyst can be heterogeneous such as a platinized electrode. [1] Homogeneous electrocatalysts, which are soluble, assist in transferring electrons between the electrode and reactants, and/or facilitate an intermediate chemical transformation described by an overall half reaction. [2] Major challenges in electrocatalysts focus on fuel cells. [3] [4]

Contents


Background and theory

An electrocatalyst lowers the activation energy required for an electrochemical reaction. [5] Some electrocatalysts change the potential at which oxidation and reduction processes occur. [6] In other cases, an electrocatalyst can impart selectivity by favoring specific chemical interaction at an electrode surface. [7] Given that electrochemical reactions occur when electrons are passed from one chemical species to another, favorable interactions at an electrode surface increase the likelihood of electrochemical transformations occurring, thus reducing the potential required to achieve these transformations. [7]

Electrocatalysts can be evaluated according to activity, stability, and selectivity. The activity of electrocatalysts can be assessed quantitatively by the current density is generated, and therefore how fast a reaction is taking place, for a given applied potential. This relationship is described with the Tafel equation. [5] In assessing the stability of electrocatalysts, the a key parameter is turnover number (TON). The selectivity of electrocatalysts refers to the product distribution. [5] Selectivity can be quantitatively assessed through a selectivity coefficient, which compares the response of the material to the desired analyte or substrate with the response to other interferents. [8]

In many electrochemical systems, including galvanic cells, fuel cells and various forms of electrolytic cells, a drawback is that they can suffer from high activation barriers. The energy diverted to overcome these activation barriers is transformed into heat. In most exothermic combustion reactions this heat would simply propagate the reaction catalytically. In a redox reaction, this heat is a useless byproduct lost to the system. The extra energy required to overcome kinetic barriers is usually described in terms of low faradaic efficiency and high overpotentials. [5] In these systems, each of the two electrodes and its associated half-cell would require its own specialized electrocatalyst. [2]

Half-reactions involving multiple steps, multiple electron transfers, and the evolution or consumption of gases in their overall chemical transformations, will often have considerable kinetic barriers. Furthermore, there is often more than one possible reaction at the surface of an electrode. For example, during the electrolysis of water, the anode can oxidize water through a two electron process to hydrogen peroxide or a four electron process to oxygen. The presence of an electrocatalyst could facilitate either of the reaction pathways. [9]

Types of electrocatalyst materials, including homogeneous and heterogeneous electrocatalysts. Types of Electrocatalysts.png
Types of electrocatalyst materials, including homogeneous and heterogeneous electrocatalysts.

Homogeneous electrocatalysts

A homogeneous electrocatalyst is one that is present in the same phase of matter as the reactants, for example, a water-soluble coordination complex catalyzing an electrochemical conversion in solution. [10] [11] This technology is not practiced commercially, but is of research interest.

Synthetic coordination complexes

Many coordination complexes catalyze electrochemical reactions, although few have achieved commercial success. Well investigated processes include the hydrogen evolution reaction. [12]

Electrification of catalytic processes

There is much interest in replacing traditional chemical catalysis with electrocatalysis. In such a scheme electrons supplied by an electrode are reagents. The topic is a theme within the area of green energy, because the electrons can be sourced from renewable resources. Several conversions that use of hydrogen gas could be transformed into electrochemical processes that use protons. [13] This technology remains economically noncompetitive. [14]

Another example is found in the area of nitrogen fixation. The traditional Haber-Bosch process produces ammonia by hydrogenation of nitrogen gas:

N2 + 3 H2 → 2 NH3

In the electrified version, the hydrogen is provided in the form of protons and electrons: [15] [16]

N2 + 6 H+ + 6 e− → 2 NH3

The ammonia represents an energy source since it is combustable. In this way electrification can be seen as a means for energy storage.

Another process attracting much effort is the electrochemical reduction of carbon dioxide. [11]

Enzymes

Some enzymes can function as electrocatalysts. [17] Nitrogenase, an enzyme that contains a MoFe cluster, can be leveraged to fix atmospheric nitrogen, i.e. convert nitrogen gas into molecules such as ammonia. Immobilizing the protein onto an electrode surface and employing an electron mediator greatly improves the efficiency of this process. [18] The effectiveness of bioelectrocatalysts generally depends on the ease of electron transport between the active site of the enzyme and the electrode surface. [17] Other enzymes provide insight for the development of synthetic catalysts. For example, formate dehydrogenase, a nickel-containing enzyme, has inspired the development of synthetic complexes with similar molecular structures for use in CO2 reduction. [19] Microbial fuel cells are another way that biological systems can be leveraged for electrocatalytic applications. [17] [20] Microbial-based systems leverage the metabolic pathways of an entire organism, rather than the activity of a specific enzyme, meaning that they can catalyze a broad range of chemical reactions. [17] Microbial fuel cells can derive current from the oxidation of substrates such as glucose, [20] and be leveraged for processes such as CO2 reduction. [17]

Heterogeneous electrocatalysts

A heterogeneous electrocatalyst is one that is present in a different phase of matter from the reactants, for example, a solid surface catalyzing a reaction in solution. Different types of heterogeneous electrocatalyst materials are shown above in green. Since heterogeneous electrocatalytic reactions need an electron transfer between the solid catalyst (typically a metal) and the electrolyte, which can be a liquid solution but also a polymer or a ceramic capable of ionic conduction, the reaction kinetics depend on both the catalyst and the electrolyte as well as on the interface between them. [7] The nature of the electrocatalyst surface determines some properties of the reaction including rate and selectivity. [7]

Bulk materials

Electrocatalysis can occur at the surface of some bulk materials, such as platinum metal. Bulk metal surfaces of gold have been employed for the decomposition methanol for hydrogen production. [2] Water electrolysis is conventionally conducted at inert bulk metal electrodes such as platinum or iridium. [21] The activity of an electrocatalyst can be tuned with a chemical modification, commonly obtained by alloying two or more metals. This is due to a change in the electronic structure, especially in the d band which is considered to be responsible for the catalytic properties of noble metals. [22]

Nanomaterials

Nanoparticles

A variety of nanoparticle materials have been demonstrated to promote various electrochemical reactions, [23] although none have been commercialized. These catalysts can be tuned with respect to their size and shape, as well as the surface strain. [24]

Electronic density difference of a Cl atom adsorbed on a Cu(111) surface obtained with a DFT simulation. Electronic density difference Cl Cu111.png
Electronic density difference of a Cl atom adsorbed on a Cu(111) surface obtained with a DFT simulation.

Also, higher reaction rates can be achieved by precisely controlling the arrangement of surface atoms: indeed, in nanometric systems, the number of available reaction sites is a better parameter than the exposed surface area in order to estimate electrocatalytic activity. Sites are the positions where the reaction could take place; the likelihood of a reaction to occur in a certain site depends on the electronic structure of the catalyst, which determines the adsorption energy of the reactants together with many other variables not yet fully clarified. [25]

According to the TSK model, the catalyst surface atoms can be classified as terrace, step or kink atoms according to their position, each characterized by a different coordination number. In principle, atoms with lower coordination number (kinks and defects) tend to be more reactive and therefore adsorb the reactants more easily: this may promote kinetics but could also depress it if the adsorbing species isn't the reactant, thus inactivating the catalyst. Advances in nanotechnology make it possible to surface engineer the catalyst so that just some desired crystal planes are exposed to reactants, maximizing the number of effective reaction sites for the desired reaction. [23]

To date, a generalized surface dependence mechanism cannot be formulated since every surface effect is strongly reaction-specific. A few classifications of reactions based on their surface dependence have been proposed [25] but there are still many exceptions that do not fall into them.

Particle size effect
An example of a particle-size effect: the number of reaction sites of different kinds depends on the size of the particle. In this four FCC nanoparticles model, the kink site between (111) and (100) planes (coordination number 6, represented by golden spheres) is 24 for all of the four different nanoparticles, while the number of other surface sites varies. Platinum nanoparticles 1 38 79 116 201.jpg
An example of a particle-size effect: the number of reaction sites of different kinds depends on the size of the particle. In this four FCC nanoparticles model, the kink site between (111) and (100) planes (coordination number 6, represented by golden spheres) is 24 for all of the four different nanoparticles, while the number of other surface sites varies.

The interest in reducing as much as possible the costs of the catalyst for electrochemical processes led to the use of fine catalyst powders since the specific surface area increases as the average particle size decreases. For instance, most common PEM fuel cells and electrolyzers design is based on a polymeric membrane charged in platinum nanoparticles as an electrocatalyst (the so-called platinum black). [26]

Although the surface area to volume ratio is commonly considered to be the main parameter relating electrocatalyst size with its activity, to understand the particle-size effect, several more phenomena need to be taken into account: [25]

  • Equilibrium shape : for any given size of a nanoparticle there is an equilibrium shape which exactly determines its crystal planes
  • Reaction sites relative number: a given size for a nanoparticle corresponds to a certain number of surface atoms and only some of them host a reaction site
  • Electronic structure : below a certain size, the work function of a nanoparticle changes and its band structure fades away
  • Defects : the crystal lattice of a small nanoparticle is perfect; thus, reactions enhanced by defects as reaction sites get slowed down as the particle size decreases
  • Stability: small nanoparticles have the tendency to lose mass due to the diffusion of their atoms towards bigger particles, according to the Ostwald ripening phenomenon
  • Capping agents: in order to stabilize nanoparticles it is necessary a capping layer, therefore part of their surface is unavailable for reactants
  • Support : nanoparticles are often fixed onto a support in order to stay in place, therefore part of their surface is unavailable for reactants

Carbon-based materials

Carbon nanotubes and graphene-based materials can be used as electrocatalysts. [27] The carbon surfaces of graphene and carbon nanotubes are well suited to the adsorption of many chemical species, which can promote certain electrocatalytic reactions. [28] In addition, their conductivity means they are good electrode materials. [28] Carbon nanotubes have a very high surface area, maximizing surface sites at which electrochemical transformations can occur. [29] Graphene can also serve as a platform for constructing composites with other kinds of nanomaterials such as single atom catalysts. [30] Because of their conductivity, carbon-based materials can potentially replace metal electrodes to perform metal-free electrocatalysis. [31]

Framework materials

Metal—organic frameworks (MOFs), especially conductive frameworks, can be used as electrocatalysts for processes such as CO2 reduction and water splitting. MOFs provide potential active sites at both metal centers and organic ligand sites. [32] They can also be functionalized, or encapsulate other materials such as nanoparticles. [32] MOFs can also be combined with carbon-based materials to form electrocatalysts. [33] Covalent organic frameworks (COFs), particularly those that contain metals, can also serve as electrocatalysts. COFs constructed from cobalt porphyrins demonstrated the ability to reduce carbon dioxide to carbon monoxide. [34]

However, many MOFs are known unstable in chemical and electrochemical conditions, making it difficult to tell if MOFs are actually catalysts or precatalysts. The real active sites of MOFs during electrocatalysis need to be analyzed comprehensively. [35]

Research on electrocatalysis

Some transition metal complexes that exhibit some activity as homogeneous electrocatalysts. Transition Metal Complex Electrocatalysts.png
Some transition metal complexes that exhibit some activity as homogeneous electrocatalysts.

Water splitting / Hydrogen evolution

A schematic of a hydrogen fuel cell. To supply hydrogen, electrocatalytic water splitting is commonly employed. Hydrogen fuel cell schematic.jpg
A schematic of a hydrogen fuel cell. To supply hydrogen, electrocatalytic water splitting is commonly employed.

Hydrogen and oxygen can be combined through by the use of a fuel cell. In this process, the reaction is broken into two half reactions which occur at separate electrodes. In this situation the reactant's energy is directly converted to electricity. Useful energy can be obtained from the thermal heat of this reaction through an internal combustion engine with an upper efficiency of 60% (for compression ratio of 10 and specific heat ratio of 1.4) based on the Otto thermodynamic cycle. It is also possible to combine the hydrogen and oxygen through redox mechanism as in the case of a fuel cell. In this process, the reaction is broken into two half-reactions which occur at separate electrodes. In this situation the reactant's energy is directly converted to electricity. [36] [37]

The standard reduction potential of hydrogen is defined as 0V, and frequently referred to as the standard hydrogen electrode (SHE). [38]

Half ReactionReduction Potential

Eored (V)

2H+ + 2e− → H2 (g)≡ 0
O2(g) + 4H+ + 4e− → 2H2O(l)+1.23

HER [10] can be promoted by many catalysts. [10]

Carbon dioxide reduction

Electrocatalysis for CO2 reduction is not practiced commercially but remains a topic of research. The reduction of CO2 into useable products is a potential way to combat climate change. Electrocatalysts can promote the reduction of carbon dioxide into methanol and other useful fuel and stock chemicals. The most valuable reduction products of CO2 are those that have a higher energy content, meaning that they can be reused as fuels. Thus, catalyst development focuses on the production of products such as methane and methanol. [11] Homogeneous catalysts, such as enzymes [19] and synthetic coordination complexes [11] have been employed for this purpose. A variety of nanomaterials have also been studied for CO2 reduction, including carbon-based materials and framework materials. [39]

Ethanol-powered fuel cells

Aqueous solutions of methanol can decompose into CO2 hydrogen gas, and water. Although this process is thermodynamically favored, the activation barrier is extremely high, so in practice this reaction is not typically observed. However, electrocatalysts can speed up this reaction greatly, making methanol a possible route to hydrogen storage for fuel cells. [2] Electrocatalysts such as gold, platinum, and various carbon-based materials have been shown to effectively catalyze this process. An electrocatalyst of platinum and rhodium on carbon backed tin-dioxide nanoparticles can break carbon bonds at room temperature with only carbon dioxide as a by-product, so that ethanol can be oxidized into the necessary hydrogen ions and electrons required to create electricity. [40]

Chemical synthesis

Electrocatalysts are used to promote certain chemical reactions to obtain synthetic products. Graphene and graphene oxides have shown promise as electrocatalytic materials for synthesis. [41] Electrocatalytic methods also have potential for polymer synthesis. [42] Electrocatalytic synthesis reactions can be performed under a constant current, constant potential, or constant cell-voltage conditions, depending on the scale and purpose of the reaction. [43]

Advanced oxidation processes in water treatment

Water treatment systems often require the degradation of hazardous compounds. These treatment processes are dubbed Advanced oxidation processes, and are key in destroying byproducts from disinfection, pesticides, and other hazardous compound. There is an emerging effort to enable these processes to destroy more tenacious compounds, especially PFAS [44]

Additional reading

See also

Related Research Articles

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References

  1. ↑ Kotrel, Stefan; BrUninger, Sigmar (2008). "Industrial Electrocatalysis". Handbook of Heterogeneous Catalysis. doi:10.1002/9783527610044.hetcat0103. ISBN   978-3527312412.
  2. 1 2 3 4 Roduner, Emil (June 13, 2017). "Selected fundamentals of catalysis and electrocatalysis in energy conversion reactions—A tutorial". Catalysis Today. 309: 263–268. doi:10.1016/j.cattod.2017.05.091. hdl: 2263/68699 . S2CID   103395714.
  3. ↑ Debe, Mark K. (2012). "Electrocatalyst approaches and challenges for automotive fuel cells". Nature. 486 (7401): 43–51. Bibcode:2012Natur.486...43D. doi:10.1038/nature11115. PMID   22678278. S2CID   4349039.
  4. ↑ Jiao, Yan; Zheng, Yao; Jaroniec, Mietek; Qiao, Shi Zhang (2015). "Design of electrocatalysts for oxygen- and hydrogen-involving energy conversion reactions". Chemical Society Reviews. 44 (8): 2060–2086. doi:10.1039/C4CS00470A. PMID   25672249.
  5. 1 2 3 4 Jaramillo, Tom (September 3, 2014). "Electrocatalysis 101 | GCEP Symposium - October 11, 2012". Youtube.com.
  6. ↑ Bard, Allen J.; Larry R. Faulkner (2001). Electrochemical methods: fundamentals and applications (Second ed.). Hoboken, NJ. ISBN   0-471-04372-9. OCLC   43859504.{{cite book}}: CS1 maint: location missing publisher (link)
  7. 1 2 3 4 McCreery, Richard L. (July 2008). "Advanced Carbon Electrode Materials for Molecular Electrochemistry". Chemical Reviews. 108 (7): 2646–2687. doi:10.1021/cr068076m. ISSN   0009-2665. PMID   18557655.
  8. ↑ Brown, Micah D.; Schoenfisch, Mark H. (2019-11-27). "Electrochemical Nitric Oxide Sensors: Principles of Design and Characterization". Chemical Reviews. 119 (22): 11551–11575. doi:10.1021/acs.chemrev.8b00797. ISSN   0009-2665. PMID   31553169. S2CID   202761809.
  9. ↑ Bard, Allen J.; Faulkner, Larry R. (January 2001). Electrochemical methods: fundamentals and applications. New York: Wiley. ISBN   978-0-471-04372-0 . Retrieved 27 February 2009.
  10. 1 2 3 4 Artero, Vincent; Chavarot-Kerlidou, Murielle; Fontecave, Marc (2011-08-01). "Splitting Water with Cobalt". Angewandte Chemie International Edition. 50 (32): 7238–7266. doi:10.1002/anie.201007987. PMID   21748828.
  11. 1 2 3 4 5 Kinzel, Niklas W.; Werlé, Christophe; Leitner, Walter (2021-01-19). "Transition Metal Complexes as Catalysts for the Electroconversion of CO 2 : An Organometallic Perspective". Angewandte Chemie International Edition. 60 (21): 11628–11686. doi: 10.1002/anie.202006988 . ISSN   1433-7851. PMC   8248444 . PMID   33464678.
  12. ↑ Wiedner, Eric S.; Appel, Aaron M.; Raugei, Simone; Shaw, Wendy J.; Bullock, R. Morris (2022). "Molecular Catalysts with Diphosphine Ligands Containing Pendant Amines". Chemical Reviews. 122 (14): 12427–12474. doi:10.1021/acs.chemrev.1c01001. OSTI   1922077. PMID   35640056.
  13. ↑ Kleinhaus, Julian T.; Wolf, Jonas; Pellumbi, Kevinjeorjios; Wickert, Leon; Viswanathan, Sangita C.; Junge Puring, Kai; Siegmund, Daniel; Apfel, Ulf-Peter (2023). "Developing electrochemical hydrogenation towards industrial application". Chemical Society Reviews. 52 (21): 7305–7332. doi:10.1039/D3CS00419H. PMID   37814786.
  14. ↑ "Dream or Reality? Electrification of the Chemical Process Industries". www.aiche-cep.com. Retrieved 2021-08-22.
  15. ↑ Guo, Wenhan; Zhang, Kexin; Liang, Zibin; Zou, Ruqiang; Xu, Qiang (2019). "Electrochemical nitrogen fixation and utilization: Theories, advanced catalyst materials and system design". Chemical Society Reviews. 48 (24): 5658–5716. doi:10.1039/C9CS00159J. PMID   31742279.
  16. ↑ Wang, Bo; Zhang, Yifeng; Minteer, Shelley D. (2023). "Renewable electron-driven bioinorganic nitrogen fixation: A superior route toward green ammonia?" (PDF). Energy & Environmental Science. 16 (2): 404–420. doi:10.1039/D2EE03132A.
  17. 1 2 3 4 5 Chen, Hui; Simoska, Olja; Lim, Koun; Grattieri, Matteo; Yuan, Mengwei; Dong, Fangyuan; Lee, Yoo Seok; Beaver, Kevin; Weliwatte, Samali; Gaffney, Erin M.; Minteer, Shelley D. (2020-12-09). "Fundamentals, Applications, and Future Directions of Bioelectrocatalysis". Chemical Reviews. 120 (23): 12903–12993. doi: 10.1021/acs.chemrev.0c00472 . ISSN   0009-2665. PMID   33050699.
  18. ↑ Milton, Ross D.; Minteer, Shelley D. (2019-12-17). "Nitrogenase Bioelectrochemistry for Synthesis Applications". Accounts of Chemical Research. 52 (12): 3351–3360. doi:10.1021/acs.accounts.9b00494. ISSN   0001-4842. PMID   31800207. S2CID   208643374.
  19. 1 2 Yang, Jenny Y.; Kerr, Tyler A.; Wang, Xinran S.; Barlow, Jeffrey M. (2020-11-18). "Reducing CO 2 to HCO 2 – at Mild Potentials: Lessons from Formate Dehydrogenase". Journal of the American Chemical Society. 142 (46): 19438–19445. Bibcode:2020JAChS.14219438Y. doi:10.1021/jacs.0c07965. ISSN   0002-7863. PMID   33141560.
  20. 1 2 Qiao, Yan; Bao, Shu-Juan; Li, Chang Ming (2010). "Electrocatalysis in microbial fuel cells—from electrode material to direct electrochemistry". Energy & Environmental Science. 3 (5): 544. doi:10.1039/b923503e. ISSN   1754-5692.
  21. ↑ Carmo, Marcelo; Fritz, David L.; Mergel, Jürgen; Stolten, Detlef (March 14, 2013). "A comprehensive review on PEM water electrolysis". International Journal of Hydrogen Energy. 38 (12): 4901–4934. Bibcode:2013IJHE...38.4901C. doi:10.1016/j.ijhydene.2013.01.151.
  22. ↑ Mistry, H.; Varela, A.S.; Strasser, P.; Cuenya, B.R. (2016). "Nanostructured electrocatalysts with tunable activity and selectivity". Nature Reviews Materials. 1 (4): 1–14. Bibcode:2016NatRM...116009M. doi:10.1038/natrevmats.2016.9.
  23. 1 2 Kleijn, Steven E. F.; Lai, Stanley C. S.; Koper, Marc T. M.; Unwin, Patrick R. (2014-04-01). "Electrochemistry of Nanoparticles". Angewandte Chemie International Edition. 53 (14): 3558–3586. doi:10.1002/anie.201306828. PMID   24574053.
  24. ↑ Luo, Mingchuan; Guo, Shaojun (September 26, 2017). "Strain-controlled electrocatalysis on multimetallic nanomaterials". Nature Reviews Materials. 2 (11): 17059. Bibcode:2017NatRM...217059L. doi:10.1038/natrevmats.2017.59. ISSN   2058-8437.
  25. 1 2 3 Koper, M.T.M. (2011). "Structure sensitivity and nanoscale effects in electrocatalysis". Nanoscale. 3 (5). The Royal Society of Chemistry: 2054–2073. Bibcode:2011Nanos...3.2054K. doi:10.1039/c0nr00857e. PMID   21399781.
  26. ↑ Carmo, M.; Fritz, D.L.; Mergel, J.; Stolten, D. (2013). "A comprehensive review on PEM water electrolysis". International Journal of Hydrogen Energy. 38 (12): 4901–4934. Bibcode:2013IJHE...38.4901C. doi:10.1016/j.ijhydene.2013.01.151.
  27. ↑ Wang, Xin (19 January 2008). "CNTs tuned to provide electrocatalyst support". Nanotechweb.org. Archived from the original on 22 January 2009. Retrieved 27 February 2009.
  28. 1 2 McCreery, Richard L. (June 17, 2008). "Advanced Carbon Electrode Materials for Molecular Electrochemistry". Chemical Reviews. 108 (7): 2646–2687. doi:10.1021/cr068076m. ISSN   0009-2665. PMID   18557655.
  29. ↑ Wildgoose, Gregory G.; Banks, Craig E.; Leventis, Henry C.; Compton, Richard G. (November 30, 2005). "Chemically Modified Carbon Nanotubes for Use in Electroanalysis". Microchimica Acta. 152 (3–4): 187–214. doi:10.1007/s00604-005-0449-x. ISSN   0026-3672. S2CID   93373402.
  30. ↑ Zhang, Qin; Zhang, Xiaoxiang; Wang, Junzhong; Wang, Congwei (2021-01-15). "Graphene-supported single-atom catalysts and applications in electrocatalysis". Nanotechnology. 32 (3): 032001. Bibcode:2021Nanot..32c2001Z. doi:10.1088/1361-6528/abbd70. ISSN   0957-4484. PMID   33002887. S2CID   222146032.
  31. ↑ Dai, Liming (June 13, 2017). "Carbon-based catalysts for metal-free electrocatalysis". Current Opinion in Electrochemistry. 4 (1): 18–25. doi: 10.1016/j.coelec.2017.06.004 .
  32. 1 2 Jiao, Long; Wang, Yang; Jiang, Hai-Long; Xu, Qiang (November 27, 2017). "Metal-Organic Frameworks as Platforms for Catalytic Applications". Advanced Materials. 30 (37): 1703663. doi:10.1002/adma.201703663. PMID   29178384. S2CID   205282723.
  33. ↑ Singh, Chanderpratap; Mukhopadhyay, Subhabrata; Hod, Idan (January 5, 2021). "Metal–organic framework derived nanomaterials for electrocatalysis: recent developments for CO2 and N2 reduction". Nano Convergence. 8 (1): 1. Bibcode:2021NanoC...8....1S. doi: 10.1186/s40580-020-00251-6 . ISSN   2196-5404. PMC   7785767 . PMID   33403521.
  34. ↑ Sharma, Rakesh Kumar; Yadav, Priya; Yadav, Manavi; Gupta, Radhika; Rana, Pooja; Srivastava, Anju; Zbořil, Radek; Varma, Rajender S.; Antonietti, Markus; Gawande, Manoj B. (2020). "Recent development of covalent organic frameworks (COFs): synthesis and catalytic (organic-electro-photo) applications". Materials Horizons. 7 (2): 411–454. doi:10.1039/C9MH00856J. ISSN   2051-6347. S2CID   204292382.
  35. ↑ Zheng, Weiran; Liu, Mengjie; Lee, Lawrence Yoon Suk (3 January 2020). "Electrochemical Instability of Metal–Organic Frameworks: In Situ Spectroelectrochemical Investigation of the Real Active Sites". ACS Catalysis. 10 (1): 81–92. doi:10.1021/acscatal.9b03790. hdl: 10397/100175 . S2CID   212979103.
  36. ↑ Kunze, Julia; Ulrich Stimming (2009). "Electrochemical Versus Heat-Engine Energy Technology: A Tribute to Wilhelm Ostwald's Visionary Statements". Angewandte Chemie International Edition. 48 (49): 9230–9237. doi: 10.1002/anie.200903603 . PMID   19894237.
  37. ↑ Haverkamp, Richard (3 June 2008). "What is an electrocatalyst?". Science learning New Zealand. Archived from the original (QuickTime video and transcript) on 29 April 2023. Retrieved 27 February 2009.
  38. ↑ Elgrishi, Noémie; Rountree, Kelley J.; McCarthy, Brian D.; Rountree, Eric S.; Eisenhart, Thomas T.; Dempsey, Jillian L. (2018-02-13). "A Practical Beginner's Guide to Cyclic Voltammetry". Journal of Chemical Education. 95 (2): 197–206. Bibcode:2018JChEd..95..197E. doi: 10.1021/acs.jchemed.7b00361 . ISSN   0021-9584.
  39. ↑ Pan, Fuping; Yang, Yang (2020). "Designing CO 2 reduction electrode materials by morphology and interface engineering". Energy & Environmental Science. 13 (8): 2275–2309. doi:10.1039/D0EE00900H. ISSN   1754-5692. S2CID   219737955.
  40. ↑ Harris, Mark (26 January 2009). "Booze-powered cars coming soon". techradar.com. Archived from the original on 2 March 2009. Retrieved 27 February 2009.
  41. ↑ Sachdeva, Harshita (2020-09-30). "Recent advances in the catalytic applications of GO/rGO for green organic synthesis". Green Processing and Synthesis. 9 (1): 515–537. doi: 10.1515/gps-2020-0055 (inactive 30 November 2024). ISSN   2191-9550.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
  42. ↑ Siu, Juno C.; Fu, Niankai; Lin, Song (2020-03-17). "Catalyzing Electrosynthesis: A Homogeneous Electrocatalytic Approach to Reaction Discovery". Accounts of Chemical Research. 53 (3): 547–560. doi:10.1021/acs.accounts.9b00529. ISSN   0001-4842. PMC   7245362 . PMID   32077681.
  43. ↑ Holade, Yaovi; Servat, Karine; Tingry, Sophie; Napporn, Teko W.; Remita, Hynd; Cornu, David; Kokoh, K. Boniface (2017-10-06). "Advances in Electrocatalysis for Energy Conversion and Synthesis of Organic Molecules". ChemPhysChem. 18 (19): 2573–2605. doi: 10.1002/cphc.201700447 . ISSN   1439-4235. PMID   28732139.
  44. ↑ Ji, Yangyuan; Choi, Youn Jeong; Fang, Yuhang; Pham, Hoang Son; Nou, Alliyan Tan; Lee, Linda S.; Niu, Junfeng; Warsinger, David M. (2023-01-19). "Electric Field-Assisted Nanofiltration for PFOA Removal with Exceptional Flux, Selectivity, and Destruction". Environmental Science & Technology. 57 (47). American Chemical Society (ACS): 18519–18528. Bibcode:2023EnST...5718519J. doi:10.1021/acs.est.2c04874. ISSN   0013-936X. PMID   36657468. S2CID   256030682.
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