Zinc oxides by thermal decomposition synthesis and parameters affecting electrocatalyst activity for CO2 reduction reaction

Electroreduction of CO₂ to obtain fossil fuel-free energy products is a promising avenue reducing anthropogenic greenhouse gas emissions. Catalysts based on Au, Ag and Cu are frequently used. Others based on abundant and low-cost elements such as Zn also report catalytic activity. This work presents a scalable and simple synthesis method of catalysts based on ZnO structures by a controlled thermal decomposition process of Zinc acetate dehydrate. An in-depth study of how modifications of synthesis parameters may affect the final performance of the material as electrocatalyst in CO₂RR is studied. It has been found that higher values of faradaic efficiency to CO evolution were found for samples synthesised at higher temperatures and higher heating ramp, reaching 69 % at -0.8 V vs RHE. It is of great importance to control over the parameters of the thermal decomposition process as they can greatly affect the final catalytic behaviour of the sample.