Precise Synthesis of Hollow Mesoporous Palladium–Sulfur Alloy Nanoparticles for Selective Catalytic Hydrogenation

Abstract

Hollow mesoporous metals have unique potentials for catalysis, but precise synthesis of the hollow mesoporous metals and further elaboration of their structure-performance relationships are still huge challenges. Herein, we report a new synthetic strategy, named as the Kirkendall effect in synergistic template (KEST), for the desired preparation of hollow mesoporous palladium-sulfur (h-mesoPdS) alloy nanoparticles. The KEST strategy combinates the Kirkendall cavitation synthesis of hollow PdS alloys at the atomic level and the nanocasting growth of highly ordered mesoporous framework at the mesoscopic level, resulting in one-step solid-phase synthesis of binary h-mesoPdS alloy nanoparticles under ambient conditions. The h-mesoPdS possesses hollow and mesoporous geometry as well as binary Pd/S alloy composition, which synergistically optimize their electronic structures and energetically adjust the hydrogenation reaction trends. The h-mesoPdS alloy nanoparticles show a remarkable selectivity of 94 % for semi-hydrogenating 4-nitrophenylacetylene to industrially important 4-nitrostyrene while without hydrogenating nitro group and over-hydrogenating alkynyl group. Owing to the big advances in both synthesis and catalysis, this work paves a new route for realizing the targeted synthesis of highly efficient nanomaterials in various applications.

Pd/CuO–Ni(OH)2/C as a highly efficient and stable catalyst for the electrocatalytic oxidation of ethanol

“…A galvanic replacement reaction would then take place, forming M 2 -on-M 1 and M 1 ions. 43,44 The difference in their redox potentials leads to the spontaneous oxidation and dissolution of metals, as well as the reduction and deposition of metal ions with a higher redox potential from the solution. Accordingly, a small amount of Cu and Ni metal atoms are replaced with Pd, so that the Pd can be deposited on the surface of Ni(OH) 2 and CuO.…”

Mesoporous Noble Metal–Metalloid/Nonmetal Alloy Nanomaterials: Designing Highly Efficient Catalysts

“…Our group recently developed a new synthetic strategy by taking advantage of Kirkendall cavitation and hard template synthesis to prepare h-mesoPdS alloy nanoparticles using mesoPd/KIT-6 as the concurrent template (Figure 3g). 60 Because the diffusion of Pd is faster than the infusion of S, the Kirkendall effect causes cavitation of mesoporous PdS alloys in a confined KIT-6 template. In addition, physical separation between reactive Pd and S by the hard KIT-6 template also simplified the synthesis through a direct solid-phase route.…”

“…In comparison to metalloid atoms, nonmetal atoms (S and P) typically have larger radii, which are thus difficult to insert into adjacent metal–metal bonds. More often, under the action of external forces, insertion promotes the rearrangement of metal atoms or directly replaces the positions of metal atoms. − The strong electronegativity of nonmetals changes the surface electronic state of adjacent metal atoms. In metal–nonmetal alloy catalysts, the synergistic effects of nonmetal components and noble metal atoms accelerate the electron transfer between different active sites, reduce the energy barrier of reaction intermediates, and adjust the binding energy of the catalyst and the reaction species. , Therefore, metal–nonmetal alloy catalysts are widely used in small-molecule electrocatalytic reactions (oxygen evolution reaction (OER), oxygen reduction reaction (ORR), EOR, HER, etc .).…”

“…(j) 4-Nitrophenylacetylene (4-NPA) conversion and product selectivity and (k) corresponding overall hydrogenation reaction trends over hollow mesoporous PdS alloy nanoparticles. Reproduced with permission from ref . Copyright 2021 Chinese Chemical Society.…”

Doping and Vacancy Engineering in a Sandwich‐like g‐C3N4/NiCo2O4 Heterostructure for Robust Oxygen Evolution

“…Hydrogen harvesting via electrochemical water splitting holds great potential for alleviating energy crisis and environmental pollution [1–3] . However, the anodic oxygen evolution reaction (OER) involves four‐electron process with sluggish kinetics and requires a high overpotential to overcome the energy barriers [4,5] .…”