Preparation of highly effective carbon black supported Pd–Pt bimetallic catalysts for nitrobenzene hydrogenation

Abstract

Carbon black (CB) supported palladium–platinum catalysts were prepared with and without nickel(II) oxide or iron(III) oxide promoter materials. By applying ultrasonic cavitation highly efficient CB supported catalysts were created. The designed catalyst preparation is a one-step procedure, as post-treatments (e.g. calcination, hydrogen activation) are not necessary. The activation of the catalysts occurs during their preparation due to the ultrasonic cavitation. Thus, a fast and simple catalyst preparation procedure have been developed. The activity of the catalysts was compared in nitrobenzene hydrogenation at different temperatures in the range of 283–323 K at 20 bar hydrogen pressure. In terms of selectivity and aniline yield, no significant differences were detected even when promoters were present. By using the NiO promoter, the activation energy was extremely low (7.6 ± 0.7 kJ mol−1). The selectivity was over 99% in every case, and 99.6% aniline yield was achieved without any promoters (99.7% with NiO), while less than 1.0% by-products were formed. The reaction rate was high with every catalyst, and no significant differences were detected. All in all, the prepared catalysts show excellent catalytic activity in the hydrogenation of nitrobenzene.

Effects of Support Types and Their Porosity Characteristics on the Catalytic Performance of Ni-Based Catalysts in Nitrobenzene Hydrogenation to Aniline

“…The detection error of the chromatograph for the organic compounds involved in this reaction system was less than 0.1%. The nitrobenzene (NB) conversion and aniline (AN) selectivity as well as the average turnover frequency (TOF) of different catalysts were calculated according to the following equations: , Conversion .25em of .25em NB = Moles .25em of .25em NB added − Moles .25em of .25em NB remained Moles .25em of .25em NB added × 100 % Selectivity .25em of .25em AN = Moles .25em of .25em AN formed Moles .25em of .25em NB added − Moles .25em of .25em NB remained × 100 % TOF = Moles .25em of .25em NB converted Moles .25em of .25em Ni × Reaction .25em time × 100 % …”

“…The detection error of the chromatograph for the organic compounds involved in this reaction system was less than 0.1%. The nitrobenzene (NB) conversion and aniline (AN) selectivity as well as the average turnover frequency (TOF) of different catalysts were calculated according to the following equations: , …”

Azide-Assisted Growth of Copper Nanostructures and Their Application as a Carbon Supported Catalyst in Two-Step Three-Component Azide–Alkyne Cycloadditions

“…Immobilizing catalysts on insoluble supports is a common approach to heterogenize catalysts to ease the separation of the catalyst from a reaction mixture and to recycle it. Carbon black (CB) has been employed as a support in different transition metal catalyzed reactions, − including single-atom or hybrid catalysts, ,, and various nanoparticle (NP)-based catalysts. − ,,, Several methods for the preparation of carbon supported Cu species have been reported, which include direct deposition of Cu NPs on carbon paper, electrodeposition, dip-coating carbon support in solutions of polymer supported Cu NPs, spin-coating, electrochemical reduction of a Cu 2 O layer, and reduction of Cu salts followed by pyrolysis , or calcination, both generating single atom catalysts. , A number of Cu NPs as heterogeneous CuAAC catalysts were further deposited on activated carbon ,,,− and graphene . Small Cu NPs for CuAAC have been also supported on Al nanofibers, and Cu clusters have been stabilized in solution by tetralkylammonium and cobaltocenium salts .…”

MIL‐100(Fe) Supported Pt−Co Nanoparticles as Active and Selective Heterogeneous Catalysts for Hydrogenation of 1,3‐Butadiene

“…Platinum (Pt) is an important transition metal and catalyst candidate due to its outstanding catalytic properties in chemical reactions [1] . In particular, Pt‐based catalysts have been widely used in hydrogenation reactions with compounds such as 1,3‐butadiene (1,3‐BD), [2] CO 2 , [3] cinnamaldehyde, [4] nitrobenzene, [5] aromatic heterocyclic compounds and carboxyl substituted aromatics, [6] tertiary amines, [7] and 5‐hydroxymethylfurfural [8] . The selective hydrogenation of 1,3‐BD is a significant industrial refining process that purifies butenes produced from crude oil cracking [9] .…”