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

Author(s)

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

Affiliation

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

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

• Document type: Journal article
• Source: ACS APPLIED MATERIALS & INTERFACES; v. 13, n. 22, p. 26001-26012, JUN 9 2021.
• Web of Science Citations: 2

Abstract

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)

• FAPESP's process: 18/01258-5 - Novel chemical catalytic and photocatalytic processes for the direct conversion of methane and CO2 to products
• Grantee: José Maria Correa Bueno
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/13821-3 - XAS time-resolved phase speciation of Cu-based Layered Double Hydroxides to ethanol dehydrogenation
• Grantee: Rodrigo Morais Menezes dos Santos
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 15/23410-5 - Copper-based layered double hydroxides for hydrogen production and other value-added products
• Grantee: Rodrigo Morais Menezes dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate