Water‐Soluble Cationic Cobalt Phthalocyanine Immobilized on SBA‐15 as a Recyclable Catalyst for Selective Oxidation of Benzylic Alcohols

The development of recyclable oxidation catalysts for the selective conversion of alcohols into value‐added aldehydes remains an important objective in catalytic chemistry. In this study, a novel water‐soluble octa‐substituted cationic cobalt phthalocyanine was synthesized and directly immobilized onto mesoporous SBA‐15 through adsorption under mild conditions, affording a recyclable heterogeneous catalyst. The resulting catalyst, Pc‐4(Co)@SBA‐15, was comprehensively characterized by FT‐IR, solid‐state UV–Vis, TG, XRD, XPS, N 2 sorption, SEM‐EDS, and TEM analyses, confirming successful immobilization while preserving the mesoporous structure of SBA‐15. The catalytic performance of Pc‐4(Co)@SBA‐15 was investigated in the selective oxidation of benzyl alcohol and various substituted benzylic alcohols. Under optimized conditions, the catalyst exhibited high aldehyde selectivity (up to 99%), with the highest conversion (59.6%) obtained for 4‐bromobenzyl alcohol. In addition, the catalyst retained most of its catalytic performance over three consecutive reaction cycles. The combination of direct immobilization, catalyst recyclability, and high aldehyde selectivity demonstrates the potential of Pc‐4(Co)@SBA‐15 as a practical heterogeneous catalyst for selective alcohol oxidation.