Cadmium Functionalized Zeolitic Imidazolate Framework (Cd-ZIF-8) Electrocatalysts for Efficient CO₂ Conversion to Syngas

The electrochemical conversion of Carbon dioxide (CO₂) into value-added fuels and chemicals represents a promising approach to mitigating greenhouse gas emissions and addressing energy demands. Among the various catalysts studied, metal-doped zeolitic imidazole frameworks (ZIFs) have emerged as effective materials for the selective electrochemical CO₂ reduction reaction (eCO₂RR). In this study, we employ a series of cadmium (Cd) doped ZIF-8 composites synthesized using a straightforward approach to enhance CO₂ electroreduction performance. The results indicate that the electroreduction of CO₂ on Cd-doped ZIF-8 catalysts facilitates the production of syngas (CO and H₂), without the generation of any liquid fuel. This leads to a total faradaic efficiency (FE) that approaches 100%. The ideal Cd−ZIF-8 composite, consisting of 10% Cd and 90% Zn, exhibits favorable selectivity with high faradaic efficiencies of 78% for CO and 22% for H₂. Additionally, the syngas ratio may be readily modified from 4:1 to 1:3 (H₂/CO) by varying the applied voltage during the CO₂ conversion procedure. This tunability highlights the potential of Cd-ZIF-8 as an efficient catalyst for customizable syngas production from CO₂. These findings open new avenues for catalyst design, supporting the development of scalable CO₂ reduction technologies aimed at environmental sustainability and renewable energy solutions.