Enhanced Hydrogenation Activity over a Zn-Modified Cu-Based Catalyst in Acetylene Hydrogenation

Abstract

The design and development of non-precious metal catalysts with excellent performance are of great significance for selective hydrogenation of acetylene from ethylene feedstock. In our previous research, a new active copper carbide (Cu x C) phase with high hydrogenation activity was synthesized by thermal treatment of acetylene-containing gas followed by hydrogen reduction. In the present work, a Zn-modified Cu x C-containing catalyst was prepared from the mixture of Cu(OH) 2 and Zn(OH) 2 by the same procedure to investigate the effect of Zn on the structure and catalytic performance of Cu x C. The addition of Zn helped to reduce the crystalline size of Cu x C and to increase the amount of Cu x C crystallites, resulting in enhanced hydrogenation activity in selective hydrogenation of acetylene. Specifically, the catalyst prepared under the optimal conditions exhibited remarkably excellent acetylene hydrogenation performance with complete acetylene conversion, low ethane selectivity (25%), and outstanding stability (>140 h) at 100 °C in the presence of large excess ethylene.

Hydrophobic Surface Modification of Cu-Based Catalysts for Enhanced Semihydrogenation of Acetylene in Excess Ethylene

“…EDX mapping (Figure f) indicated a significant decrease in the oxygen signal and an increase in the carbon signal in Cu 2 O-C 16 R, attributed to Cu 2 O reduction in the hydrogen environment and CuC x formation. XRD analysis (Figure g) further confirmed the conversion from Cu 2 O to Cu and CuC x , with a characteristic broad peak at 37° and a distinct peak at 43° corresponding to CuC x and Cu, respectively. − Additionally, X-ray photoelectron spectroscopy (XPS) was utilized to explore the electronic structure variation of Cu 2 O-C 16 after the reaction. Cu 2p XPS spectra revealed Cu + and Cu 0 species on the Cu 2 O-C 16 R surface (Figure h), as confirmed by Cu LMM Auger spectra dominance of Cu + (Figure i). , Considering the absence of Cu 2 O diffraction peaks in the XRD pattern and the prevalence of the Cu + signal, attributed to CuC x , these findings align with the structure presented in Figure e.…”

Synthetic Strategies of Supported Pd-Based Bimetallic Catalysts for Selective Semi-Hydrogenation of Acetylene: A Review and Perspectives

“…However, using this process route, a trace amount of acetylene is inevitably produced as a by-product. Unfortunately, the acetylene impurity (usually in the range of 0.1~2 vol.%) contained in the ethylene raw material does great harm during the production of the downstream derivatives of ethylene [ 1 , 4 , 5 , 6 , 7 , 8 ]. The trace amount of C 2 H 2 , easily and irreversibly deactivates the Ziegler–Natta catalysts of ethylene polymerization, which sharply degrades the eventual quality of the ethylene-derived polymers.…”

“…The trace amount of C 2 H 2 , easily and irreversibly deactivates the Ziegler–Natta catalysts of ethylene polymerization, which sharply degrades the eventual quality of the ethylene-derived polymers. In addition, it also easily forms explosive oligomers, which brings safety risks to the downstream reaction systems [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. In this context, the acetylene concentration is required to be removed to less than 5 ppm to meet the downstream production demand [ 1 , 4 , 5 , 8 ].…”

“…In this context, the acetylene concentration is required to be removed to less than 5 ppm to meet the downstream production demand [ 1 , 4 , 5 , 8 ]. Acetylene impurities could be removed by several methods, among which the catalytically selective semi-hydrogenation to ethylene is the most widely used way in the industry due to its good economy, environmental friendliness, and convenience [ 5 , 6 , 9 ]. On the other hand, in academia, acetylene hydrogenation has also attracted much attention from researchers because it is usually selected to serve as a model reaction of selective hydrogenation to evaluate the performance and catalytic mechanism of catalysts [ 10 ].…”

Anchoring ultrasmall Pd nanoparticles by bipyridine functional covalent organic frameworks for semihydrogenation of acetylene

“…Although Fe, Cu, Zn and other non-noble metal-based catalysts have long been used in hydrogenation reactions, [5][6][7] satisfactory activity is hard to obtain at low temperatures. In contrast, the substitution by Pd, a typical noble metal, overcomes the limit of temperature successfully.…”