Thiol Treatment Creates Selective Palladium Catalysts for Semihydrogenation of Internal Alkynes

Abstract

Surface and interfacial engineering of heterogeneous metal catalysts is effective and critical for optimizing selective hydrogenation for fine chemicals. By using thiol-treated ultrathin Pd nanosheets as a model catalyst, we demonstrate the development of stable, efficient, and selective Pd catalysts for semihydrogenation of internal alkynes. In the hydrogenation of 1-phenyl-1-propyne, the thiol-treated Pd nanosheets exhibited excellent catalytic selectivity (>97%) toward the semihydrogenation product (1-phenyl-1-propene). The catalyst was highly stable and showed no obvious decay in either activity or selectivity for over ten cycles. Systematic studies demonstrated that a unique Pd-sulfide/ thiolate interface created by the thiol treatment was crucial to the semihydrogenation. The high catalytic selectivity and activity benefited from the combined steric and electronic effects that inhibited the deeper hydrogenation of C=C bonds. More importantly, this thiol treatment strategy is applicable to creating highly active and selective practical catalysts from commercial Pd/C catalysts for semihydrogenation of internal alkynes.

Breaking Trade‐Off between Selectivity and Activity of Nickel‐Based Hydrogenation Catalysts by Tuning Both Steric Effect and d‐Band Center

“…As shown in Figure a,b, Ni 2p and P 2p spectra of SPhF‐Ni 2 P exhibit several typical fitted characteristic peaks of Ni 2 P . S 2p spectra of SPhF‐Ni 2 P shows a symmetrical peak at 163.78 eV assigned to Ni‐S‐R, suggesting a single chemical environment around S atoms (Figure S16a, Supporting Information). Moreover, the S 2p signal of SPhF‐Ni 2 P disappears after etched by argon sputtering (Figure S16b, Supporting Information), confirming SPhF molecules only exist on Ni 2 P surface.…”

“…And the Van der Waals interaction between benzene rings of SPhF and reactants may further enhance the adsorption of reactants. More importantly, the electronegative elements of organic molecules are expected to push the d‐band center of Ni away from the Fermi level, which can lower the antibonding energy level and consequently strengthen the interaction between Ni 2 P and H 2 , beneficial for hydrogen activation . Therefore, Ni‐based catalysts chelated by SPhF‐array may achieve the goal of hitting two birds with one stone, namely, boost both the selectivity and activity simultaneously, which provides the possibility to break the trade‐off between activity and selectivity for hydrogenation of chemicals containing conjugated alkene bond.…”

Exploring Bi2Te3 Nanoplates as Versatile Catalysts for Electrochemical Reduction of Small Molecules

“…Therefore, the atomic arrangement of the activated Bi 2 Te 3 NPs/C showed obvious structure change at the surface, which would affect the catalytic performance. [ 44,45 ] In addition, the discontinuous lattice formed by the obvious Te dissolution could lead to the formation of Te vacancies. As revealed by X‐ray photoelectron spectroscopy (XPS; Figure S18, Supporting Information), as for Bi 2 Te 3 NPs/C, the atom ratio of surface Bi and Te was 24.58/75.42.…”

Robust Synthesis of Gold‐Based Multishell Structures as Plasmonic Catalysts for Selective Hydrogenation of 4‐Nitrostyrene

“…ForS -PTSAu/ZrO 2 ,t he catalytic activity was greatly weakened (Supporting Information, Figure S12b), which is not surprising as the poison ability of sulfhydryl group in reducing PSS. [4,32] More importantly,t he overhydrogenation reaction was prevented in S-PTSAu/ZrO 2 system (Supporting Information, Figure S12b). The NH 3 ·BH 3 -initiated hydrogenation of am ixture of nitrobenzene and styrene was further tested using two catalysts.T he results (Supporting Information, Table S1) show that PTSAu/ ZrO 2 are active towards reduction of Ar-NO 2 and Ar-C = C, while the S-PTSAu/ZrO 2 activate only Ar-NO 2, not Ar-C = C. Thetransfer hydrogenation processes have been proposed in AB-initiated hydrogenation reactions.…”