Titanium‐Microfiber‐Supported Binary‐Oxide Nanocomposite with a Large Highly Active Interface for the Gas‐Phase Selective Oxidation of Benzyl Alcohol

Abstract

AbstractThin‐sheet sinter‐locked Ti‐microfiber‐supported binary‐oxide‐nanocomposite catalysts engineered on the micro‐ to macroscales were developed for the gas‐phase aerobic oxidation of benzyl alcohol to benzaldehyde. The catalysts demonstrated higher activity than single‐oxide and noble‐metal catalysts with good stability and regenerability. The catalysts were obtained by placing transient metal (e.g., Ni, Co, Cu, Mn) nitrates onto a Ti‐microfiber surface by impregnation, and the supported nitrates were subsequently in situ transformed into the binary‐oxide composites in the real reaction stream at 300 °C. Among them, CoO‐2.5–CuOx‐2.5/Ti‐fiber was found to be the best catalyst; it delivered 93.5 % conversion of benzyl alcohol (b.p. 210 °C) with 99.2 % selectivity to benzaldehyde at 230 °C. In situ induced formation of “CoO@Cu2O” ensembles (i.e., larger CoO nanoparticles partially covered with smaller Cu2O clusters and/or nanoparticles) was identified, which by nature resulted in a large Cu2O–CoO interface and led to a significant improvement in the low‐temperature activity.