Cu-based catalysts are widely used for methanol synthesis due to their high conversion and selectivity.cuo/zno/al2o3 catalyst A successful industrial Cu-based methanol production process requires a stable catalyst that is capable of operating under continuous reaction conditions for long periods of time.cuo/zno/al2o3 catalyst The selection of a suitable support and the control of catalyst deactivation are critical for successful commercialization of this process. Several studies have demonstrated that copper-alumina (Cu/Al2O3) is a promising methanol catalyst. However, the factors that determine the catalytic activity of Cu/Al2O3 have not been clearly elucidated.
In this study, the kinetic behavior of a commercially active Cu/ZnO/Al2O3 catalyst was investigated under different reaction conditions to reveal the underlying mechanisms of deactivation.cuo/zno/al2o3 catalyst The results showed that the catalytic performance of the Cu/ZnO/Al2O3 system is significantly influenced by the presence of non-metal ions.cuo/zno/al2o3 catalyst This effect is a function of both the nature of the ions and the structure of the catalyst. The methanol conversion and selectivity of the Cu/ZnO/Al2O3 complex were found to depend on the amount of CO2 present in the reaction medium. It was also shown that the catalytic performance of the catalyst deteriorated as the reaction progressed, which is related to changes in the physicochemical properties of the metal oxide particles.
To improve the characterization of Cu/ZnO/Al2O3 at the atomic scale, a high-resolution aberration-corrected STEM technique was utilized to observe the distribution of metallic Cu particles and their surface coverage on the alumina substrate.cuo/zno/al2o3 catalyst Using this method, it was demonstrated that the Cu/ZnO/Al2O3 composite exhibits a high surface area with good dispersion of metal particles. The redox potential and the Cu particle size were also determined by N2O chemisorption and X-ray photoelectron spectroscopy, respectively.
The results of N2O chemisorption revealed that the methanol selectivity of the CZMNZA catalyst is mainly determined by the ratio of Cu+ to Cu0 species.cuo/zno/al2o3 catalyst This is in line with previous studies, indicating that the Cu/ZnO/Al2O3 catalysis is highly dependent on the intrinsic reactivity of Cu and the occurrence of Cu+ species (Baltes et al., 2008; Dong et al., 2016; Dasireddy and Likozar, 2019).
D.cuo/zno/al2o3 catalyst L. conceived the project, performed the experiments, and wrote the manuscript. F. Xu and P.T. conducted the EDX analysis and TEM measurements, respectively. X.L. and S.D. contributed to the characterization of the ZnO overlayer, and X. Tang contributed to the X-ray photoelectron spectra measurements. The adsorption of ions on the catalyst was investigated by DFT calculations, which were carried out by all coauthors. The authors acknowledge funding from the National Natural Science Foundation of China (NSFC) and the Strategic Priority Research Program of the Chinese Academy of Sciences. The authors would like to thank the anonymous reviewers for their helpful comments on this article. The authors declare no conflicts of interest. The data presented in this paper is freely available to all interested researchers upon request. Please contact the corresponding author for further details. This article contains supplemental information online at the journal website.
Tags:cuznal methanol catalyst | hy zeolite catalyst | palladium catalyst | zeolite catalyst
