Copper Supported on Ceria Mesocellular Foam Silica as an Effective Catalyst for Reductive Condensation of Acetone to Methyl Isobutyl Ketone

Abstract

Copper-containing materials based on Ce-and Ca-Nb-mesocellular foam (MCF) silica supports are prepared, characterized and applied as catalysts for gas-phase reductive condensation of acetone to produce methyl isobutyl ketone (MIBK). The properties of the materials, the interaction of metal species, and their role in the catalytic process are examined by nitrogen physisorption, XRD, XPS, CO 2 -TPD, H 2 -TPR, and chemisorption of NO and pyridine combined with FTIR spectroscopy. A syner-gistic interaction of Cu 2 + , Cu 0 , and CeO 2 species incorporated in the MCF support enable the Cu/Ce-MCF catalyst to yield 34 % of acetone conversion with over 90 % MIBK selectivity at 250 °C. Moreover, this high catalyst selectivity is maintained during operation for 24 h despite a decline in catalyst activity. The catalytic performance is superior to that of hydroxyapatitesupported Cu and similar previously reported Pd-containing catalysts.

Leveraging the Proximity and Distribution of Cu−Cs Sites for Direct Conversion of Methanol to Esters/Aldehydes

“…The chemical states of Cu and Cs were characterized by X‐ray photoelectron spectroscopy (XPS) and auger electron spectrum (AES). It can be seen in Figure 4f that Cu/SiO 2 exhibits remarkable Cu 2+ 2p 3/2 peak at 935.0 eV as well as Cu 2+ satellite peak at 940–945 eV in Cu 2p XPS spectra, [39] which are much more intense than those of Cu−Cs/SiO 2 . Owing to the similar binding energy between Cu 0 and Cu 1+ species in XPS spectra, the overlapping peaks in Cu LMM AES spectra (Figure 4g) were further deconvoluted to discriminate Cu species, in which Cu/SiO 2 and Cu−Cs/SiO 2 exhibit similar distributions of Cu 0 and Cu 1+ species.…”