Insights into the Preparation of Copper Catalysts Supported on Layered Double Hydroxide Derived Mixed Oxides for Ethanol Dehydrogenation

Autor(es)

Santos, Rodrigo M. M. ^{[1, 2]} ; Briois, Valerie ^[1] ; Martins, Leandro ^[2] ; Santilli, V, Celso

Afiliação do(s) autor(es)

^[1] SOLEIL Synchrotron, BP48, F-91192 Gif Sur Yvette - France

^[2] V, Sao Paulo State Univ UNESP, Inst Chem, BR-14800060 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ACS APPLIED MATERIALS & INTERFACES; v. 13, n. 22, p. 26001-26012, JUN 9 2021.
• Citações Web of Science: 2

Resumo

Acetaldehyde is an important chemical commodity and a building block for producing several other high-value products in the chemical industry. This has motivated the search for suitable, efficient, stable, and selective catalysts, as well as renewable raw materials such as ethanol. In this work, supported copper catalysts were prepared from CuZnAI layered double hydroxides (LDHs) with different copper contents (5, 10, and 20 wt %) for application in the ethanol dehydrogenation reaction (EDR). The samples were thoroughly characterized by a series of techniques, which allowed for analysis of all of the copper and zinc species involved in the different catalyst preparation steps and during the EDR. The results obtained by in situ quick extended X-ray absorption fine structure (EXAFS) measurements, combined with multivariate data analysis, showed that the copper content in the pristine LDH influenced the phase composition of the mixed oxide support, which consequently affected the dispersion of copper nanoparticles. The higher the copper content, the higher are the ZnAl2O4 and zinc tetrahedral prenuclei (TPN) contents, to the detriment of the ZnO content. All the samples showed high selectivity (>97%) and stability in the catalytic reactions at 300 and 350 degrees C, with no observed deactivation during 6 h on-stream. Although the samples with lower copper content presented higher copper dispersion and reactivity, the sample containing 20 wt % of copper outperformed the others, with greater conversion and higher activity toward acetaldehyde. (AU)

• Processo FAPESP: 18/01258-5 - Novos processos catalíticos e fotocatalíticos para a conversão direta de metano e CO2 em produtos
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