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.