Constructing fully exposed Pt atomically dispersed catalysts for enhanced multifunctional selective hydrogenation reactions

Abstract

Constructing highly efficient and low-cost catalysts is essential for the selective hydrogenation reaction. Herein, we developed fully exposed Pt atomically dispersed catalysts (PtAD/C-Al2O3) by a simple carbon modified strategy. Importantly, the co-existence of Pt-O1C2 single atoms and Pt nanoclusters in the PtAD/C-Al2O3 system could exhibit excellent catalytic activity in the selective hydrogenation of quinoline and p-nitrophenol. Notably, the quinoline conversion and the corresponding selectivity of 1,2,3,4-tetrahydroquinoline is 99.6 % and 99.3 %, respectively. Meanwhile, the turnover frequency of PtAD/C-Al2O3 (1081 h−1) is 3.8 and 5.7 times higher than that of Pt single-atom catalysts (PtSA/C-Al2O3) and Pt nanoparticles (PtNPs/C-Al2O3), respectively, during quinoline hydrogenation. Besides, the rate constant of PtAD/C-Al2O3 could reach 192.5 min-1mgPt-1 for p-nitrophenol hydrogenation, which is much better than most of the reported catalysts. Mechanism studies revealed the synergistic effect between Pt-O1C2 single atoms and Pt nanoclusters acts as the main role in enhancing the hydrogenation activity. Specifically, Pt single atoms sites mainly adsorb and activate quinoline molecules, while Pt nanoclusters boost the dissociation of H2 molecules to H atoms. This work paves an origin carbon modified method to construct Pt atomically dispersed catalysts for efficient multifunctional hydrogenation.