Ultradeep Removal of Acetaldehyde from Ethanol through Catalytic Hydrogenation with Highly Dispersed Ag Nanoparticles Supported on Phenyl-Modified SiO₂

Ethanol-based drinks and disinfectants are widely consumed around the world. Acetaldehyde (AA) is the main impurity in ethanol, which is also a representative volatile organic compound (VOC). Increased attention should be paid to the potential harm caused by AA in ethanol due to the significant increase of AA exposure even in nondrinkers. With Ag nanoparticles (NPs) being supported on the phenyl group-modified silica (Ag/Ph-SiO₂) as the catalyst, which was prepared by a simple one-pot reverse-phase microemulsion method, a catalytic hydrogenation removal strategy has been illustrated in the present work to ultradeeply remove AA in ethanol. The introduction of phenyl groups facilitated the distribution of Ag NPs, the formation of the pore structure, and the improvement of the surface affinity to AA molecules, which are beneficial for the adsorption and conversion of AA in ethanol. The AA content in ethanol could be controlled to be below 0.1 ppm at 90 °C in 5 h under 3 MPa H₂ pressure. The safety of ethanol-based products is believed to be greatly improved with the present technology.