CO 2 reduction reaction (CO 2 RR) is a promising technique for mitigating global warming and storing renewable energy if it can be obtained with a highly selective, efficient, and durable electrocatalyst. Here, we report CO 2 RR catalyzed by Au nanoparticles (NPs) stabilized by pyridines and pyrimidines (e.g., 2-mercaptopyridine (2Mpy), 4-mercaptopyridine (4Mpy), and 2-mercaptopyrimidine (2Mpym)) on a nanostructured carbon-doped TiO 2 nanowire (NanoCOT) electrode, which has been previously reported by our team for electrocatalytic water oxidation. An online gas chromatography (GC) set-up with improved gaseous product sensitivity with real-time pressure monitoring is used to quantify CO and hydrogen products from the Au NP-modified NanoCOT electrode. High CO selectivity is observed at Au-2Mpy coated NanoCOT electrode. CO 2 reduction products are not observed at bare NanoCOT suggesting CO 2 is reduced at the Au nanoparticle sites of the electrode. Moreover, CH 3 OH is not detected at the Au-Mpy/Mpym NPs during rotating ring disk electrode (RRDE) analysis which implies pyridine attached to the Au NPs has no catalytic effects on CO 2 RR as claimed by others in the literature. A durable complete H-cell using a NanoCOT anode and Au NP-NanoCOT cathode electrodes is assembled for complete water splitting, CO 2 RR, and stability test. 
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                            Synergies between electronic and geometric effects of Mo-doped Au nanoparticles for effective CO 2 electrochemical reduction
                        
                    
    
            CO 2 electroreduction is developing as a promising technology to solve environmental and energy problems. Alloy catalysts with dissimilar local metal atoms induce geometric and electronic effects that may greatly contribute to their performance. However, the fundamental mechanisms for CO 2 reduction on a bimetallic Au alloy surface are still ambiguous. Here, we report effective CO 2 reduction by the synergies between electronic and geometric effects of Mo-doped Au nanoparticles (MDA NPs). A 97.5% CO faradaic efficiency and 75-fold higher current density than pure Au nanoparticles were achieved at −0.4 V versus the reversible hydrogen electrode for MDA NPs with at least 50 h lifetime. Our experimental and theoretical calculation results reveal that the Au surface with increased electron density from Mo can effectively enhance CO 2 activation. Moreover, the intermediate *COOH may be further stabilized by the local Mo atom through additional Mo–O binding to decrease the energy barrier. 
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                            - Award ID(s):
- 1900039
- PAR ID:
- 10185810
- Date Published:
- Journal Name:
- Journal of Materials Chemistry A
- Volume:
- 8
- Issue:
- 25
- ISSN:
- 2050-7488
- Page Range / eLocation ID:
- 12291 to 12295
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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