Zhu Fulong, Li Junqing, Zhu Mingyuan, Kang Lihua
College of Chemistry & Chemical Engineering, Yantai University, Yantai 264010, China.
School of Chemistry and Chemical Engineering of Shihezi University, Shihezi 832003, China.
Nanomaterials (Basel). 2021 Apr 29;11(5):1174. doi: 10.3390/nano11051174.
In this study, a series of activated carbon-based supports with different oxygen-containing groups (OCGs) proportions were obtained via thermal treatment in an ozone flow. Semiquantitative analyses indicated that the performance of the catalyst attained a maximum after 30 min of treatment with ozone flow, and had a positive correlation with the content ratios of carboxyl and hydroxyl groups. Further, temperature-programmed desorption analysis demonstrated that the high performance (63% acetic acid conversion) of the prepared catalyst for the acetoxylation of acetylene could be ascribed to the reduced strength of increased capacity of acetylene adsorption. Density functional theory proved that the additional -COOH in the dicarboxylic catalytic system could be employed as a support for the active sites, and enhancing CH adsorption strength in the rate-limiting step in the actual experimental process effectively accelerated the reaction rate. Thus, the OCGs on the surface of activated carbon play a crucial role in the catalytic performance of the acetylene acetoxylation catalyst.
在本研究中，通过在臭氧流中进行热处理，获得了一系列具有不同含氧基团（OCGs）比例的活性炭基载体。半定量分析表明，在臭氧流处理30分钟后，催化剂的性能达到最大值，并且与羧基和羟基的含量比呈正相关。此外，程序升温脱附分析表明，所制备的催化剂用于乙炔乙酰氧基化反应的高性能（63%的乙酸转化率）可归因于乙炔吸附容量增加而强度降低。密度泛函理论证明，二羧酸催化体系中额外的-COOH可作为活性位点的载体，并且在实际实验过程中，增强限速步骤中的CH吸附强度有效地加速了反应速率。因此，活性炭表面的OCGs对乙炔乙酰氧基化催化剂的催化性能起着关键作用。
