posted on 2024-01-16, 14:39authored byZhengwen Li, Jiajun Zhang, Jiaming Tian, Kai Feng, Yuxin Chen, Xiao Li, Zhihe Zhang, Shuairen Qian, Bin Yang, Dong Su, Kai Hong Luo, Binhang Yan
Achieving
high ethylene selectivity while preserving high reactivity
for semihydrogenation of acetylene over Pd-based catalysts is still
challenging. Here, we propose a structure of encapsulated Pd nanoparticles
to enhance catalytic performance via a low-dose doping-segregation
strategy using Pd-doped SrTiO3 as a precursor. The encapsulated
Pd nanoclusters are revealed to be protected by a thin TiOx shell to prevent contact with acetylene/ethylene.
However, hydrogen can still be efficiently activated on the encapsulated
Pd sites and react with the adsorbed acetylene on surface Ti3+ sites via hydrogen spillover. By taking advantage of weaker ethylene
adsorption on partially reduced oxide TiOx, this catalyst shows an enhanced performance of 98% conversion and
92% selectivity with a specific activity of 5552 molC2H2·molPd–1·h–1 at 100 °C, significantly surpassing most Pd-based catalysts.
This strategy decouples active sites for the activation of different
reactants, providing a thought for the development of highly active
and selective hydrogenation catalysts.