A Novel High-Activity Zn-Co Catalyst for Acetylene Acetoxylation

Abstract

In this paper, Zn(OAc) 2 /AC and Zn-Co/AC catalysts were prepared and applied in an acetylene acetoxylation reaction. Compared with monometallic Zn(OAc) 2 /AC catalyst, which is widely applied in industry, the Zn-Co catalysts exhibited excellent catalytic performance. Transmission electron microscopy results displayed that the addition of cobalt improved the dispersity of zinc acetate particles and inhibited catalyst sintering on the catalyst surface. X-ray photoelectron spectra suggested that the Co additive changed the electron density of zinc acetate probably because of the interaction between Zn and Co species. Temperature programmed desorption analysis demonstrated Co additive strengthened the adsorption of acetic acid and weakened the adsorption of acetylene.

Effect of Oxygen-Containing Group on the Catalytic Performance of Zn/C Catalyst for Acetylene Acetoxylation

“…These results revealed that the existence of a dicarboxylic system reduced the adsorption strength of C 2 H 2 on the catalysts, and this corresponded to the TPD results ( Figure 7 a). Additionally, to correlate the actual experimental process to the possible mechanism [ 8 , 9 , 11 ], a hypothetical model was developed for the adsorption of acetylene during the reaction. As shown in Figure 9 (a 1 ), a molecule of CH 3 COOH was first adsorbed on the monocarboxylic catalyst to form a complex.…”

“…Regarding this mechanism, the rate-limiting step is the adsorption of acetylene [ 6 ]. Some scholars [ 7 , 8 , 9 ] have demonstrated that the adsorption strength and capacity of acetylene significantly influences the acetylene acetoxylation reaction. Thus, the regulation of the adsorption of acetylene must be considered in the field of catalysis science.…”

“…Thus, the regulation of the adsorption of acetylene must be considered in the field of catalysis science. Thus far, various studies on the supports and catalysts of the acetylene acetoxylation reaction, including N [ 9 , 10 ] and B-doped ACs [ 11 ] as the support and metal additives [ 8 ], have been developed through the density functional theory (DFT) investigation [ 7 ]. Further, heteroatom-doping via the introduction of heteroatoms such as B [ 11 ] and N [ 9 , 10 ], has been employed to change the surface electronic structure of AC and adjust the interaction among the different atoms inside, changing the adsorption capability of the catalyst and improving the conversion rate of acetic acid.…”

“…The roles of different OCGs have been revealed superficially by demonstrating that the reaction barriers of the rate-limiting step in this case was reduced by the existence of –COOH. Although many scholars achieved slightly positive results on the acetoxylation of acetylene, the following series of challenges still exist: the low conversion of acetic acid and the mechanization of OCGs [ 8 , 9 ]; the slightly higher OCGs contents cause the low utilization of the zinc component [ 10 ] and the DFT results of OCGs have not been effectively supported experimentally [ 7 ]. Whether the specific influence of OCGs on the acetoxylation of acetylene is due to the interaction of OCGs with zinc, electron transfer, or other phenomena such as the adsorption capacity, which strongly impacts the catalytic performance of the catalyst, there are no experimental data and characterization measures available.…”

Performance Study of Zn-Co-Ni/AC Catalyst in Acetylene Acetylation

“…A type of catalyst containing nitrogen with high activity was prepared by Yu et al [20]. Wang and coworkers [21,22] used zinc-cobalt and zinc-nickel as active components and explained the relevant reaction mechanisms. Wang et al [23] prepared nitrogen-doped AC by modifying AC with dicyandiamide (N-AC) and used it for loading Zn(OAc) 2 , which exhibited good performance.…”