Atomic overlayer of permeable microporous cuprous oxide on palladium promotes hydrogenation catalysis

Abstract

The interfacial sites of metal-support interface have been considered to be limited to the atomic region of metal/support perimeter, despite their high importance in catalysis. By using single-crystal surface and nanocrystal as model catalysts, we now demonstrate that the overgrowth of atomic-thick Cu2O on metal readily creates a two-dimensional (2D) microporous interface with Pd to enhance the hydrogenation catalysis. With the hydrogenation confined within the 2D Cu2O/Pd interface, the catalyst exhibits outstanding activity and selectivity in the semi-hydrogenation of alkynes. Alloying Cu(0) with Pd under the overlayer is the major contributor to the enhanced activity due to the electronic modulation to weaken the H adsorption. Moreover, the boundary or defective sites on the Cu2O overlayer can be passivated by terminal alkynes, reinforcing the chemical stability of Cu2O and thus the catalytic stability toward hydrogenation. The deep understanding allows us to extend the interfacial sites far beyond the metal/support perimeter and provide new vectors for catalyst optimization through 2D interface interaction.

Tripodal Pd metallenes mediated by Nb2C MXenes for boosting alkynes semihydrogenation

“…Above these results substantiated the heterolytic activation of H 2 yielded hydrogen proton at Pd/Nb 2 C. It was generally accepted that heterolytic activation of H 2 would be related to the Pd-O interface. According to the results of EXAFS for Pd/Nb 2 C, the existence of Pd-O was the essential factor for heterolytic activation 52,57 , again corroborating the formation of Pd metallene structure.…”

Host–Guest Chemistry in Discrete Polyoxo-12-Palladate(II) Cubes [MO8Pd12L8]n− (M = ScIII, CoII, CuII, L = AsO43 –; M = CdII, HgII, L = PhAsO32–): Structure, Magnetism, and Catalytic Hydrogenation

“…Given the respective surface energies of the metals (Cu = 1.790 < Pd = 2.050 J·m –2 ), the copper in CuPd 12 As 8 would prefer to segregate to the surface of the CuPd alloy nanoparticles . Based on related studies, the resultant CuPd alloy might partially weaken the adsorption energy of H atoms and thereby accelerate the subsequent hydrogenation reaction of the substrate . To obtain further insight into the CuPd alloy nanoparticles in the present work, we studied the oxidation states of Pd and Cu in CuPd 12 As 8 -SBA-15-apts before and after catalysis by means of XPS.…”

Two-Dimensional Nanomaterial-Templated Composites

“…74 As a result, fcc Au@Pt rhombic core−shell nanoplates exposing a unique (101) f basal plane and a small amount of fcc Au@Pt square core−shell nanoplates with a novel (100) f orientation (Figure 4 Specifically, Rh nanorods can be selectively deposited on different regions of Au nanosheets, i.e., two 2H/fcc heterophase basal planes and two pairs of opposite edges with fcc phase and 2H/fcc heterophase, respectively, leading to the rational construction of three kinds of distinct 1D/2D Rh−Au composites (Figure 4k). In addition to the aforementioned metal−metal heterostructures, the synthesis of other composites consisting of 2D metal templates and metal compounds, e.g., MOFs, 75 metal oxides, 76 metal hydroxides, 77 etc., has also been explored. For example, Zhang et al achieved the preparation of a novel Pd/MOF Janus structure via the selective growth of a MOF on one basal plane of Pd nanosheets.…”

“…In addition to the aforementioned metal–metal heterostructures, the synthesis of other composites consisting of 2D metal templates and metal compounds, e.g. , MOFs, metal oxides, metal hydroxides, etc. , has also been explored.…”