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Thin films of Ni 3 Al and Ni 3 Ga on carbon solid supports have been shown to generate multi-carbon products in electrochemical CO 2 reduction, an activity profile that, until recently, was ascribed exclusively to Cu-based catalysts. This catalytic behavior has introduced questions regarding the role of each metal, as well as other system components, during CO 2 reduction. Here, the significance of electrode structure and solid support choice in determining higher- versus lower-order reduction products is explored, and the commonly invoked Fischer–Tropsch-type mechanism of CO 2 reduction to multi-carbon products is indirectly probed. Electrochemical studies of both intermetallic and non-mixed Ni–Group 13 catalyst films suggest that intermetallic character is required to achieve C2 and C3 products irrespective of carbon support choice, negating the possibility of separate metal sites performing distinct yet complementary roles in CO 2 reduction. Furthermore, Ni 3 Al and Ni 3 Ga were shown to be incapable of generating higher-order reduction products in D 2 O, suggesting a departure from accepted mechanisms for CO 2 reduction on Cu. Additional routes to multi-carbon products may therefore be accessible when developing intermetallic catalysts for CO 2 electroreduction.
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Organic photoredox catalysts for CO 2 reduction: Driving discovery with genetic algorithms
This work implements a genetic algorithm (GA) to discover organic catalysts for photoredox CO 2 reduction that are both highly active and resistant to degradation. The lowest unoccupied molecular orbital energy of the ground state catalyst is chosen as the activity descriptor and the average Mulliken charge on all ring carbons is chosen as the descriptor for resistance to degradation via carboxylation (both obtained using density functional theory) to construct the fitness function of the GA. We combine the results of multiple GA runs, each based on different relative weighting of the two descriptors, and rigorously assess GA performance by calculating electron transfer barriers to CO 2 reduction. A large majority of GA predictions exhibit improved performance relative to experimentally studied o-, m-, and p-terphenyl catalysts. Based on stringent cutoffs imposed on the average charge, barrier to electron transfer to CO 2 , and excitation energy, we recommend 25 catalysts for further experimental investigation of viability toward photoredox CO 2 reduction.
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- Award ID(s):
- 2102044
- PAR ID:
- 10345298
- Date Published:
- Journal Name:
- The Journal of Chemical Physics
- Volume:
- 156
- Issue:
- 18
- ISSN:
- 0021-9606
- Page Range / eLocation ID:
- 184109
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1063/5.0088353
