Research on Silane-Free CO2 Hydroformylation: Reaction Mechanisms with Ru3(CO)12 and Phosphine Catalysts

Abstract

Global warming has spurred interest in CO₂ utilization. Coupling reverse water–gas shift (RWGS) with hydroformylation allows olefins to react with H₂/CO₂ to produce valuable aldehydes, which is a profitable reaction and helps with carbon fixation. However, temperature mismatch between the two reactions and limited mechanistic understanding hinder the rational design of catalysts. Using density functional theory (DFT) calculations and experimental evaluations, we investigated the effects of different phosphine ligands and acid additives on the performance of silane-free CO₂ hydroformylation. Formic acid alters the CO₂ activation pathway and reduces the energy barrier, thereby improving catalytic activity and chemoselectivity. The effects of reaction conditions reveal a competitive relationship between CO₂ reduction and olefin carbonylation, suggesting that balancing RWGS and hydroformylation rates enhances catalytic performance. Our work not only deepens the mechanism understanding of silane-free CO₂ hydroformylation but also paves the way for the rational design of subsequent high-performance catalysts.