Transition Metal Nitrides as Promising Catalyst Supports for Tuning CO/H 2 Syngas Production from Electrochemical CO 2 Reduction

• Published in: Angewandte Chemie (International ed.) 2020-07, Vol.59 (28), p.11345-11348
• Main Authors: Liu, Yumeng, Tian, Dong, Biswas, Akash N, Xie, Zhenhua, Hwang, Sooyeon, Lee, Ji Hoon, Meng, Hong, Chen, Jingguang G
• Format: Article
• Language: English
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202003625

The electrochemical carbon dioxide reduction reaction (CO RR) to produce synthesis gas (syngas) with tunable CO/H ratios has been studied by supporting Pd catalysts on transition metal nitride (TMN) substrates. Combining experimental measurements and density functional theory (DFT) calculations, Pd-modified niobium nitride (Pd/NbN) is found to generate much higher CO and H partial current densities and greater CO Faradaic efficiency than Pd-modified vanadium nitride (Pd/VN) and commercial Pd/C catalysts. In-situ X-ray diffraction identifies the formation of PdH in Pd/NbN and Pd/C under CO RR conditions, whereas the Pd in Pd/VN is not fully transformed into the active PdH phase. DFT calculations show that the stabilized *HOCO and weakened *CO intermediates on PdH/NbN are critical to achieving higher CO RR activity. This work suggests that NbN is a promising substrate to modify Pd, resulting in an enhanced electrochemical conversion of CO to syngas with a potential reduction in precious metal loading.