A heterogeneous catalyst was synthesized by supporting copper metal on MCM-41 by chemical vapor deposition (CVD). The usage of oxygen as a carrier gas and oxidizing agent is found to be very important in producing a stable and effective Cu/MCM-41 catalyst. This MCM-41-supported copper catalyst is evaluated in the photo-Fenton-like degradation of a dye pollutant, Orange II. Results show that the Cu/MCM-41 catalyst is effective in mineralizing total organic carbon (TOC) of 80%, 78%, and 70% at pH 3, 5.5, and 7, respectively, successfully overcoming the low efficiency problem of the conventional Fenton reaction at high pH. Moreover, the synthesized catalyst is proved to be durable with a stable TOC removal efficiency after four consecutive cycles. The kinetic study of pollutant degradation using Cu/MCM-41 is also conducted.