Synthesis and characterization of copper impregnated mesoporous carbon as heterogeneous catalyst for phenylacetylene carboxylation with carbon dioxide

Carbon dioxide (CO₂) is a compound that can potentially be used as a carbon source in the synthesis of fine chemicals. However, the utilization of CO₂ is still constrained due to its inert and stable nature. Therefore, the presence of a catalyst is needed in CO₂ conversion. This study aims to synthesize copper impregnated mesoporous carbon (Cu/MC) as a catalyst for phenylacetylene carboxylation reaction with CO₂ to produce phenylpropiolic acid. The synthesis of mesoporous carbon was performed via the soft template method. The as-synthesized Cu/MC material was characterized by FTIR, SAA, XRD, and SEM-EDX. BET surface area analysis of mesoporous carbon showed that the material has a high surface area of 405.8 m²/g with an average pore diameter of 7.2 nm. XRD pattern of Cu/MC indicates that Cu has been successfully impregnated in the form of Cu(0) and Cu(I). Phenylacetylene carboxylation reaction with CO₂ was carried out by varying reaction temperatures (25, 50, and 75 °C), amount of catalyst (28.6, 57.2, and 85.8 mg), type of base (Cs₂CO₃, K₂CO₃, and Na₂CO₃), and variation of support. The reaction mixtures were analyzed by HPLC and showed that the highest phenylacetylene conversion of 41% was obtained for the reaction at 75 °C using Cs₂CO₃ as a base.