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Nanostructured Pd−Cu Catalysts Supported on Zr−Al and Zr−Ti for Synthesis of Vinyl Acetate
Author(s) -
Gonzalez Caranton Alberth Renne,
Dille Jean,
Barreto Jade,
Stavale Fernando,
Pinto José Carlos,
Schmal Martin
Publication year - 2018
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201801083
Subject(s) - catalysis , acetic acid , ethylene , decomposition , metal , copper , chemistry , dehydration , inorganic chemistry , x ray photoelectron spectroscopy , nuclear chemistry , organic chemistry , chemical engineering , biochemistry , engineering
Renewable ethylene can be obtained by dehydration of bio‐ethanol and used for production of vinyl acetate (VAM) through reaction with acetic acid (AcOH), using Pd−Cu catalysts. In the present manuscript, structural characterizations of Pd−Cu/ZrO 2 catalysts show that these systems present cubic structure with different spatial distributions. Particularly, it is shown that combustion of ethylene and acetic acid can be inhibited below 180 °C, maximizing the rates of VAM formation, when the catalysts are modified with Ti +4 . The effects of AcOH concentration on rates of VAM formation show that higher AcOH concentrations favor the formation of undesired byproducts, while lower AcOH concentrations favor effects related to O 2 mobility, which can lead to surface decomposition. VAM formation is favored, with selectivities ranging from 0.8 to 1.0. XPS results indicate the existence of metallic Pd, CuO species and Zr species, in agreement with IR results. DRIFTS results also show that different Pd‐acetate intermediates can be present, depending on the electronic effects associated to Pd−Cu and Zr species.