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.