Bimetallic NiAg supported on aminopropyl-functionalized periodic mesoporous organosilica as a reusable catalyst for CO2 conversion to value-added chemicals

Transforming CO2 into more valuable chemicals has gained great interest due to greenhouse gas and climate change related issues. In this study, we performed CO2 hydrogenation using a bimetallic nickel-silver catalyst supported on periodic mesoporous organosilica (NiAg/NH2-pr-Ph-PMO). The NH2pr-Ph-PMO was prepared via a co-condensation method, and NiAg was was incorporated using a simple wet impregnation process. Physicochemical properties of the catalyst were thoroughly characterized using FTIR, XRD, SEM-EDX, TEM, and BET-BJH. The synthesized NiAg/NH2pr-Ph-PMO exhibited excellent properties, including a large surface area (793.5 m2/g) and uniform metal distribution. The optimal conditions for CO2 hydrogenation found in this study were 225 °C, 2 bar, and a CO2/H2 ratio of 1:5. Under these conditions, conversion of CO2 reached 38.34 % with 86.89 % selectivity towards formaldehyde production. Furthermore, NiAg/NH2pr-Ph-PMO exhibits fine catalytic stability with the CO2 conversion maintained above 35 % after 4 reaction cycles. FTIR analysis indicates no significant structural damage on the used catalyst, highlighting its robustness. This study showcases the excellent performance of the novel catalyst in converting CO2 into more valuable chemicals.