Copper Single-Atom-Covered Pt Nanoparticles for Selective Hydrogenation of Phenylacetylene

Abstract

The selective hydrogenation of alkynes to alkenes is very important for both industry and scientific investigation, and overhydrogenation of alkynes to alkanes is the biggest problem to be solved. Suppressing the catalytic hydrogenation of alkenes to alkanes and keeping the efficient conversion from alkynes to alkenes at the same time is a viable solution, but the slight difference in structure between alkynes and the corresponding alkenes causes great difficulty in realizing such a target. The Pt/C− Cu bimetallic catalysts are used to catalyze the selective hydrogenation of phenylacetylene (PA) to styrene (ST). Highresolution STEM and EXAFS results show that the prepared Pt/ C−Cu catalysts are composed of copper single atoms and Pt nanoparticles. In particular, Pt/C−Cu is a catalyst in which copper single atoms cover the surface of Pt nanoparticles. The experimental results reveal that the selectivity of ST strongly depends on the coverage of Cu single atoms over Pt nanoparticles in Pt/C−Cu, so selective hydrogenation of PA is a structure-sensitive reaction. The selectivity of ST can reach 94.4% at a PA conversion of 100% in the selective hydrogenation of PA over Pt/C−0.5Cu, an optimized Pt−Cu bimetallic catalyst; after selective removal of PA in ST from 100 to 30 ppm over the same catalyst, the yield of ST reaches 99.97%. The chemisorption results of H 2 and probe molecule ethene (C 2 H 4 ) over the Pt−Cu/C catalysts reveal that Cu single atoms covering on the surface of Pt nanoparticles weaken the Pt−H and Pt−C 2 H 4 interactions, so the catalytic hydrogenation of the carbon−carbon double bond over Pt/C−0.5Cu can be tremendously suppressed. The added Cu single atoms over Pt nanoparticles are not poisonous sites because they can also act as the active centers to activate hydrogen and the carbon−carbon double bond.

A Magnetically Separable Pd Single‐Atom Catalyst for Efficient Selective Hydrogenation of Phenylacetylene

“…Therefore, selective hydrogenation (e.g., semi-hydrogenation) of phenylacetylene to styrene was employed before styrene polymerization. [3][4][5][6] However, undesired byproducts like alkanes are inevitably generated due to overhydrogenation. So, it is urgent to develop novel catalysts with both high selectivity and activity for semihydrogenation of phenylacetylene.…”

Promotion Effect of the X-Zeolite Host on Encapsulated Platinum Clusters for Selective Hydrogenation of Phenylacetylene to Styrene

“…It is generally accepted that palladium catalysts are mostly used to achieve a high catalytic performance for this reaction. Yet, it is difficult to design platinum-based catalysts that have good catalytic performance due to their low selectivity and poor stability. , The biggest problem is that the overhydrogenation of phenylacetylene to phenylethane often occurs in the platinum catalyst due to the weak cooperation of the active sites and the support environment, thus resulting in the catalytic hydrogenation of styrene that cannot be effectively avoided. − …”

Direct Bonding of CpCo- Fragments on Pt Nanoparticles and their Electronic Effect for Alkyne Semihydrogenation

“…Impressively, the TOF value increases after the CpCo- fragments bonding on Pt/SiO 2 and further increases with the CpCo- coverage. The highest TOF on 200CpCo-Pt/SiO 2 (17 964.0 h –1 ) is also higher than most reported Pt and Pd-based catalysts. − In addition, the reusability of 200CpCo-Pt/SiO 2 was tested. It is found that the selectivity and conversion are nearly similar after the consecutive recycling runs (Figure S14c).…”