Effective modification of Pd surfaces with TiO₂ promoters using selective chemical vapor deposition and the effect on catalytic performance improvement

In this paper, we describe a novel method for selectively attaching TiO₂ promoters on Pd surfaces in Pd/SiO₂ catalysts using selective chemical vapor deposition (CVD). Ti was selectively deposited on Pd active sites over a SiO₂ support under a hydrogen atmosphere when titanium tetraisopropoxide was used as a Ti precursor. The Pd-Ti/SiO₂ catalyst modified by CVD exhibits approximately 1.8 times higher ethylene selectivity than the un-modified Pd/SiO₂ catalyst in the selective hydrogenation of acetylene due to the effective geometric modification of the Pd surface, which is beneficial to ethylene selectivity, by the selectively deposited Ti species.