Different Dimensional MOFs‐Derived Defect Engineering for Highly Selective Electrocatalytic Reduction

Abstract Approximately 4% of global carbon dioxide emissions originate from methane‐to‐hydrogen technologies used in industrial hydrogenation reactions. Therefore, electrocatalytic hydrogenation (ECH) technologies utilizing green hydrogen sources are gradually receiving widespread attention. How to inhibit the hydrogen evolution reaction (HER) by regulating the microenvironment in order to enhance the ECH efficiency is of great importance for environmental protection and sustainable industrial development. In this study, the in situ spatial dimension control strategy is utilized to modulate the growth of Cobalt‐based metal–organic frameworks (Co‐MOFs) with varied dimensions on copper foam (CF), thereby regulating the vacancy defects in the carriers to optimize the electronic state of the active sites. Notably, the catalyst derived from two‐dimensional (2D Co‐ZIF‐L with abundant pyridinic‐N vacancy defects exhibits excellent selectivity (82%) and high faradaic efficiency (FE, 66%) in the selective ECH of biomass molecules. In addition, uncovering the differences in the electronic states of active sites is key to achieving targeted adsorption and activation of reaction sites in ECH. Rationally selecting MOF‐derived catalysts with different dimensions provides an effective way to regulate the microenvironment of metal nanoparticles (NPs).