Palladium-Copper bimetallic catalysts for electroreduction of CO2 and nitrogenous species

The rapid surge in global population and fossil fuel utilization over the past two centuries have disrupted the natural carbon and nitrogen cycles, leading to various environmental problems, such as the greenhouse effect, ocean acidification, and water pollution. Electrocatalytic technologies driven by renewable electricity offer great potential for solving these problems. Nonetheless, the formidable stability of CO2 and nitrogenous species (e.g., N2, NH3, and NO3-) poses a substantial obstacle when devising efficient electrocatalysts for large-scale applications. Bimetallic electrocatalysts offer the advantage of adjustable geometric and electronic structures, enabling the adsorption of crucial intermediates involved in various reactions, thus displaying enhanced catalytic activity and selectivity in comparison to their single-element counterparts. This review focuses on recent progresses in Palladium-Copper based bimetallic catalysts used in electrocatalysis CO2 reduction reaction, N2 reduction reaction, nitrate reduction reaction, and N-integrated CO2 reduction reaction. Furthermore, the influence of composition, interface, morphology, and supports of Pd-Cu catalysts on the catalytic performance in these reactions is systematically summarized. Finally, the challenges and opportunities in designing and mechanism understanding of Pd-Cu bimetallic catalysts have been discussed, with the aim to inspire the rational construction of advanced bimetallic electrocatalysts, and broaden the product scope in electrocatalysis.