Regulating Aromatic Alcohols Distributions by Cofeeding Methanol with Ethanol over Cobalt-Hydroxyapatite Catalyst

Graphical Direct production of benzyl alcohol : The distribution of aromatic alcohols on cobalt-hydroxyapatite is greatly switched from methylbenzyl alcohol (feeding ethanol) to benzaldehyde (C 7 , BA=O) and benzyl alcohol (C 7 , BA−OH) by cofeeding of methanol and ethanol. Aromatic alcohols, often used for the synthesis of plasticizers, coatings and pharmaceuticals, are currently produced from the oxidation of petroleum-derived aromatic hydrocarbons. Herein, we report a non-petroleum and environmentally friendly route for the production of aromatic alcohols: cofeeding methanol with ethanol over cobalt-hydroxyapatite catalyst, in which the distribution of aromatic alcohols products can be regulated by varying methanol pressure. Co species on hydroxyapatite can activate both methanol and ethanol to yield their corresponding aldehydes (formaldehyde and acetaldehyde). The followed cross- and self-condensations of aldehydes are catalyzed by hydroxyapatite to produce acrolein and 2-butenal, which are the key intermediates for the formation of aromatic oxygenates. The sequential cross-condensation and dehydrocyclization of acrolein and 2-butenal yield benzaldehyde, which is then hydrogenated to benzyl alcohol. The direct production of benzyl alcohol from methanol and ethanol could be regarded as a cutting-edge example, which ensures a promising route for sustainable aromatic alcohols production.