Exploring Heterostructures of D-Block Metal Oxides Coupled to ZnO for the Electrochemical Reduction of CO₂

Abstract

Feasible electrochemical CO2 reduction (ECR) requires accessible and efficient catalyst materials. Herein, we prepared ZnO-based catalysts decorated with various d-block metal oxides (Fe, Co, Ni, Cu). The ECR performance of the heterostructured catalyst materials was evaluated by using a flow-cell configuration. Our findings indicate that ZnO is an active catalyst substrate with tunable selectivity and stability, which depend on the formed heterostructures’ properties. We assessed and quantified the effect of the different d-block metals on the ECR activity of the composite catalyst. The Cu-ZnO catalyst exhibited a stability of 30 h and a selectivity of 77% for CO at a current density of 100 mA cm–2. This work aimed to provide a fundamental understanding of composite heterostructured materials’ properties and electrochemical behavior. We demonstrated that heterostructure engineering is a promising and cost-effective strategy for developing ECR catalysts with enhanced stability.

Photocatalytic Efficiency for CO2 Reduction of Co and Cluster Co2O2 Supported on g-C3N4: A Density Functional Theory and Machine Learning Study

“…Numerous studies, both computational and experimental, have been conducted to find efficient photocatalysts for CO 2 reduction. − Among such candidate materials, considerable effort has been devoted to the investigation of structures composed of metal nanoclusters, or single-atom catalysts, deposited on surfaces, in order to minimize material usage. Indeed, experimental realization of these structures on, e.g., metal-oxide-based materials − (including TiO 2 , ZnO, BiVO 4 , CeO 2 , and Cu 2 O) and organic-based-semiconductor surfaces − such as g-C 3 N 4 , accompanied by extensive theoretical analyses, ,, proved the very good catalytic activity of these materials for CO 2 reduction. In this context, structures deposited on organic-based semiconductors have become of great interest due to their comparable performance to traditional metal-oxide photocatalysts, while featuring a lower production cost, higher stability, and simpler synthesis. − …”

Light-Driven and Electrochemical CO2 Reduction

“…These show how careful management of acid/base chemistry together with stabilization of the desired intermediates can tune the selectivity and efficiency of the reactions. , They also show how the choices of support and electrode material are important. − CO 2 reduction is particularly challenging because the reactions involve three phases: gaseous reactant, solid electrode, and liquid electrolyte . Articles in this Collection illustrate the opportunities and challenges provided by gas diffusion electrodes. , Clever design of the electrode structure and composition has been used to optimize the electrochemical reactions and prevent flooding, a common issue limiting the stability of these systems. − …”