B-doped activated carbon as a support for a high-performance Zn-based catalyst in acetylene acetoxylation

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

“…This implied that the high performance of the Zn/AC-30 catalyst was mainly ascribed to the high adsorption capacity and an appropriate adsorption strength. Moreover, the enhanced adsorption of CH 3 COOH also impacted the performances of the catalysts significantly, as demonstrated by a previous study [ 11 ], and implied that the supernumerary –COOH group could promote the absorption capacity of C 2 H 2 on the active sites post ozone treatment. It is also possible that additional –COOH groups could change the adsorption strength of C 2 H 2 within the reaction duration.…”

“…Further, the desorption temperature of C 2 H 2 distinctly reduced from 629.6 K (the Zn/AC catalyst) to 620.7 K (the Zn/AC-30 catalyst). Based on our previous studies [ 11 ], the decrease in the desorption temperature played a positive role in the acetoxylation of acetylene. Furthermore, the desorption area of the Zn/AC-30 catalyst was much larger than that of the Zn/AC catalyst, i.e., the adsorption capacity of C 2 H 2 by the catalyst was apparently enhanced after the ozone treatment for 30 min.…”

“…TPD analysis was employed to further understand the reasons for the high performances of the catalysts (TPD details: Appendix B ) [ 11 ]. As shown in Figure 7 a, the adsorption capacity of C 2 H 2 by the catalysts changed after the ozone treatment compared with that of Zn/AC.…”

“…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.…”

“…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. Dong et al [ 7 ] calculated the bond energy between zinc acetate and different oxygen-containing groups (OCGs) and estimated the complexity of the reaction that occurred in the active sites (zinc acetate that was adsorbed on the hydroxyl (–OH) and carboxyl (–COOH)).…”