Synergistic H2 activation and structural stabilization by Ag doping in CoO catalysts for enhanced dicyclopentadiene hydroformylation

Abstract

Tricyclodecanemonoaldehyde (TCDMA) and tricyclodecanedialdehyde (TCDDA) are key intermediates in fine chemicals and are typically synthesized via hydroformylation of dicyclopentadiene (DCPD). However, developing cost-effective and highly active catalysts with high selectivity remains a significant challenge. A series of M-doped CoO catalysts (M = Ag, Cu, Fe, Ni) are synthesized via a co-precipitation method for DCPD hydroformylation, and Ag is identified as the optimal dopant for synergistic regulation of CoO catalytic performance. The structure–activity relationships of the catalysts are systematically elucidated using a combination of characterization techniques, including XRD, SEM/TEM, in situ FTIR, H₂-TPD, H₂-TPR, and CO-TPR, and the reaction conditions (temperature, catalyst dosage, pressure, and time) are systematically optimized. Under the optimal reaction conditions (150 °C, 7 MPa, 24 h), the 10% Ag/CoO catalyst achieves a DCPD conversion of 72%, a total aldehyde selectivity of 90%, and a combined yield of TCDMA + TCDDA of over 65%. The introduction of Ag nanoparticles not only modulates the surface electronic structure of CoO to promote H₂ adsorption and activation but also suppresses the excessive reduction and aggregation of cobalt active species during the reaction, thereby enhancing both catalytic activity and structural stability. Based on experimental characterization and performance evaluation, a dynamic catalytic cycle mechanism for DCPD hydroformylation on the Ag/CoO surface is proposed, clarifying the synergistic catalytic effects of Ag and CoO active sites. Compared with traditional precious metal catalysts, the Ag/CoO bimetallic catalyst features low cost, simple preparation, and excellent catalytic performance and exhibits significant potential for industrial application in the green synthesis of TCDMA and TCDDA.