Mixed metal oxide (MMO) represents a critical class of materials that can allow for obtaining a dynamic interface between its components: reduced metal and its metal oxide counterpart during an electrocatalytic reaction. Here, a synthetic method utilizing a MOF-derived micro/mesoporous carbon as a template to prepare sub-2 nm MMO catalysts for CO2 electroreduction is reported. Starting from the zeolite imidazolate framework (ZIF-8), the pyrolyzed derivatives were used to synthesize sub-2 nm Pd-Ni MMO with different compositions. The Ni-rich (Pd20-Ni80/ZC) catalyst exhibits unexpectedly superior performance for CO production with an improved Faradaic efficiency (FE) of 95.3% at the current density of 200 mA cm−2 at −0.56 V vs. reversible hydrogen electrode (RHE) compared to other Pd-Ni compositions. X-ray photoelectron spectroscopy (XPS) analysis confirms the presence of Ni2+ and Pd2+ in all compositions, demonstrating the presence of MMO. Density functional theory (DFT) calculation reveals that the lower CO binding energy on the surface of the Pd20-Ni80 cluster eases CO desorption, thus increasing its production. This work provides a general synthetic strategy for MMO electrocatalysts and can pave a new way for screening multimetallic catalysts with a dynamic electrochemical interface.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government (MSIT) ( RS-2023-00210114 ). This research was supported by the National R&D Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science and ICT ( 2021M3D1A2051636 ). This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) ( NRF-2021R1C1C1004264 and NRF-2021R1A4A1032114 ). This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government (MSIT) ( NRF-2022R1A4A1019296 ).
© 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences
- Carbon dioxide reduction
- Carbon monoxide
- Metal-organic framework
- Mixed metal oxide
ASJC Scopus subject areas
- Fuel Technology
- Energy Engineering and Power Technology
- Energy (miscellaneous)