Nanoengineered Design of inside‐Heating Hot Nanoreactor Surrounded by Cool Environment for Selective Hydrogenations

Abstract

Catalysts with designable intelligent nanostructure may potentially drive the changes in chemical reaction techniques. Herein, a multi‐function integrating nanocatalyst, Pt‐containing magnetic yolk‐shell carbonaceous structure, having catalysis function, microenvironment heating, thermal insulation, and elevated pressure into a whole is designed, which induces selective hydrogenation within heating‐constrained nanoreactors surrounded by ambient environment. As a demonstration, carbonyl of α, β‐unsaturated aldehydes/ketones are selectively hydrogenated to unsaturated alcohols with a >98% selectivity at a nearly complete conversion under mild conditions of 40 °C and 3 bar instead of harsh requirements of 120 °C and 30 bar. It is creatively demonstrated that the locally increased temperature and endogenous pressure (estimated as ≈120 °C, 9.7 bar) in the nano‐sized space greatly facilitate the reaction kinetics under an alternating magnetic field. The outward‐diffused products to the “cool environment” remain thermodynamically stable, avoiding the over‐hydrogenation that often occurs under constantly heated conditions of 120 °C. Regulation of the electronic state of Pt by sulfur doping of carbon allows selective chemical adsorption of the CO group and consequently leads to selective hydrogenation. It is expected that such a multi‐function integrated catalyst provides an ideal platform for precisely operating a variety of organic liquid‐phase transformations under mild reaction conditions.

Hydrogen Spillover-Driven Dynamic Evolution and Migration of Iron Oxide for Structure Regulation of Versatile Magnetic Nanocatalysts

“…Magnetic nanocatalysts, a crucial group of smart catalytic materials, have attracted extensive attention due to their ability in controllable magnetic separation, − induced heating, − promoting spin-selective electron transfer, and magnetic levitation. − Magnetic nanocatalysts are usually prepared by impregnating magnetic nanoparticles onto the support alone or in combination with other active sites, e.g., noble metals. However, these exposed magnetic nanoparticles are not stable in air and easily react with acid media, resulting in a change or loss of their magnetization.…”