Synthesis of Pd–Co_xO_y Hybrid Nanostructure-Encapsulated Hollow Silica Nanospheres through Reverse Microemulsion Systems and Their Application as Efficient Hydrodechlorination Catalysts

Abstract

Pd–Co x O y heteroaggregate-encapsulated hollow porous silica nanoreactors (Pd–Co x O y @HPSNs) were synthesized by a reverse microemulsion system. The key design of the developed reverse microemulsion system is to use poly(ethyleneimine) in the water droplets as the void templates for silica deposition and for anchoring the catalytic functionality inside the hollow silica nanospheres. The synthesized Pd–Co x O y @HPSNs contain ∼3 nm Pd–Co x O y hybrid nanostructures in ∼10 nm central cavities of silica nanospheres and illustrated a significantly promoted efficiency for hydrodechlorination of a series of chlorophenols into phenols under mild reaction conditions. The catalytic enhancement of Pd–Co x O y @HPSNs is ascribed to the synergistic effect between Pd and Co x O y and the protection of silica shells to the inner catalytic functionality.

One‐pot Construction of Metal Nanoparticles Loaded COF Catalysts for Aqueous Hydrogenation Reactions

“…The adoption of COFs with specific functional groups and uniform pore size is critical for the anchor of metal NPs and their following hydrogenation application. Although either NaBH 4 , [43] or H 2 [44] or HCOOH [45] has been reported to work as hydrogen donor, the expensive, dangerous and corrosive features limit their practical applications. [46][47][48] In our case, ammonium formate (AF) is employed as an alternative one due to its low cost, safety and availability.…”

TiO2 Coating on SiO2 Nanosphere Supported Pd Catalyst for the H2–SCR of NOx in the Presence of Oxygen

“…33,38 Compared with 0.5Pd/TiO 2 , the peak position over 0.5Pd/SiO 2 −TiO 2 (C) was shifted to lower binding energy by ∼0.5 eV, which suggests a stronger interaction existed between Pd and SiO 2 − TiO 2 (C). 9,39 The XPS speaks for 0.5Pd/SiO 2 −TiO 2 (C) can be divided into three separate peaks at 335.5, 336.6, and 341.8 eV, which are ascribed to Pd 0 and Pd 2+ , respectively. 7 The Pd 0 / (Pd 0 + Pd 2+ ) ratio over 0.5Pd/SiO 2 −TiO 2 (C) was about 6.2%.…”

Precision Synthesis of Sub-3 nm Bimetallic Alloy Nanoparticles for Efficient and Selective Catalytic Hydrogenolysis of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran

“…Consequently, this synthesis yields ultrasmall bimetallic alloy nanoparticles with exceeding merits: exceptional size and compositional homogeneity, continuous tunability, and fully exposed metal surfaces. Previous studies have reported the synthesis of encapsulated metal nanoparticles in microemulsion systems, but most focused on monometallic metal nanoparticles, typically showing broad size distributions and often exhibiting multicore–shell configurations. − Our experimental design, with thermodynamic control over both wet chemical and thermal alloying processes, enables the synthesis of ultrasmall bimetallic alloy nanoparticles with high precision, laying the foundation for fully controlling their catalytic properties. We demonstrate the outstanding catalytic performance of 1.2 nm-PtCo alloy nanoparticles in the chemoselective hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF), an ideal platform for the synthesis of sustainable liquid fuels and chemicals from cellulose-derived HMF .…”