Copper Nanoparticle Confinement in P-Doped Carbon Nitride Templates Enables Efficient Peroxymonosulfate Activation for Alcohol Oxidation

Abstract

Controlling the particle size and stability under reaction conditions is crucial for increasing catalyst lifetime and producing more sustainable chemical processes. In this work, Cu oxide nanoparticles were confined in three distinct supports: MCF (mesocellular foam) silica, layers of carbon nitride on the surface of mesoporous silica (MCF-CN), or layers of P-doped carbon nitride (MCF-CN-P). The carbon nitride coating was produced using cyanamide, and P-doped carbon nitride was created from a mixture of cyanamide and sodium hypophosphite. The different supports were used to investigate their effects on the distribution, size, and stability of Cu-based particles in the selective oxidation of alcohols, employing peroxymonosulfate (PMS) as the oxidizing agent. Primary and secondary alcohols such as cyclohexanol, benzyl alcohol, and 4-hydroxy-3,5-dimethoxybenzyl alcohol were used as substrates. The synthesized layers of P-doped carbon nitride enhance the conversion of alcohols to their respective ketones or aldehydes, achieving conversions above 80% and selectivity above 90%. Moreover, the stability of copper oxide increases compared with particles deposited on pristine silica.