It
is challenging to develop an alkyne semi-hydrogenation catalyst
with both high selectivity and high activity, especially at low temperatures
and low pressures. Herein, a single-atom Ni-modified Al2O3-supported Pd is proposed as a modulation strategy to
optimize the selectivity of alkyne semi-hydrogenation. Sphere-difference-corrected
transmission electron microscopy and synchrotron radiation confirm
that Ni single atoms enter the alumina lattice in a highly dispersed
state, while Pd is loaded on the Ni-modified support in the form of
nanoparticles. For the semi-hydrogenation of phenylacetylene, the
Pd0.5/Ni0.5@γ-Al2O3 catalyst with Pd and Ni loadings of 0.45 and 0.43 wt %, respectively,
achieves 98% conversion and 94% selectivity at 298 K and 0.1 MPa.
It also possesses good stability, as the activity remains unchanged
after 10 cycles of application. The Pd0.5/Ni0.5@γ-Al2O3 catalyst inherits the high activity
of Pd and the high selectivity of Ni to achieve efficient semi-hydrogenation
of phenylacetylene at low temperatures and pressures, benefiting from
the synergistic effect of Pd and Ni.
Electrocatalytic production of hydrogen peroxide (H2O2) by 2e- oxygen reduction (ORR) is a clean on-site method. Although doped carbon materials have been widely used in hydrogen peroxide research, few studies...
Abstract2D metallene nanomaterials have spurred considerable attention in heterogeneous catalysis by virtue of sufficient unsaturated metal atoms, high specific surface area and surface strain. Nevertheless, the strong metallic bonding in nanoparticles aggravates the difficulty in the controllable regulation of the geometry of metallenes. Here we propose an efficient galvanic replacement strategy to construct Pd metallenes loaded on Nb2C MXenes at room temperature, which is triggered by strong metal-support interaction based on MD simulations. The Pd metallenes feature a chair structure of six-membered ring with the coordination number of Pd as low as 3. Coverage-dependent kinetic analysis based on first-principles calculations reveals that the tripodal Pd metallenes promote the diffusion of alkene and inhibit its overhydrogenation. As a consequence, Pd/Nb2C delivers an outstanding turnover frequency of 10372 h−1 and a high selectivity of 96% at 25 oC in the semihydrogenation of alkynes without compromising the stability. This strategy is general and scalable considering the plentiful members of the MXene family, which can set a foundation for the design of novel supported-metallene catalysts for demanding transformations.
Modulation of the metal-support interaction plays a key role in many important chemical reactions. Here, by adjusting the reduction method of the catalyst and introducing oxygen vacancies in TiO2 to...
The limited reserves and sluggish H2O dissociation process of Pt necessitates the development of low-cost catalysts with enhanced catalytic performance in alkaline hydrogen evolution reaction. Here, Ru nanoparticles supported on...
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