This study is led by Dr. Yunxiang Lin (Anhui University), Dr. Xiyu Li (Great Bay university), Dr. Hengjie Liu, and Prof. Li Song (University of Science and Technology of China). In this work, the authors reported a strategy for regulating the hydrogen bond network at the electrolyte-electrode interface during the electrocatalytic co-reduction of CO2 and H2O.
The CO2RR is a proton-coupled electron transfer (PCET) process, where protons originating from water molecules at the electrolyte–electrode interface play a crucial role in the reaction. Hence, in addition to reducing energy barriers, enhancing the kinetics of the PCET steps is an important strategy to enhance CO2RR. One method involves introducing long-chain molecules into the electrolyte to modify the hydrogen bond network at the electrode surface during the CO2RR process. Another approach involves creating neighboring active sites (e.g., adjacent single-atom sites) to enhance water dissociation and ensure an adequate supply of protons. This strategy of regulating dissociating water molecules to improve catalytic performance can considerably expand the potential for material design and fabrication in complex PCET processes.
To effectively accelerate the PCET process, the cubic phase molybdenum carbide with favorable water dissociation capacity, was selected to modify the adjacent microenvironment of cobalt phthalocyanine to facilitate the proton generation and transfer. A series of in-situ characterizations further confirmed the rearrangement of interface water and the rapid transformation of intermediates. Additionally, theoretical simulations indicate that the incorporation of cubic phase molybdenum carbide nanoparticles can effectively change the adsorption behavior of water molecules near the CoPc molecules, resulting in accelerated proton transfer in the hydrogen bond network.
Dr. Yunxiang Lin and the collaborators integrate in-situ synchrotron radiation characterizations and theoretical simulations to provide a simple yet effective venue to track the forming of dense interfacial hydrogen bond network during the reaction and probe the intrinsic mechanism regarding proton generation and fast transfer.
