Interactions of phenol and benzaldehyde in electrocatalytic upgrading process

Abstract

Biomass pyrolysis oil can be improved effectively by electrocatalytic hydrogenation (ECH). However, the unclear interactions among different components lead to low bio-oil upgrading efficiency in the conversion process. Herein, benzaldehyde and phenol, as common compounds in bio-oil, were chosen as model compounds. The interactions between the two components were explored in the ECH process by combining experiments and theoretical calculations. Results showed that phenol could accelerate the conversion of benzaldehyde in the ECH. The selectivity of benzyl alcohol was increased from 60.9% of unadded phenol to 99.1% with 30 mmol/L phenol concentration at 5 h. Benzaldehyde inhibited the ECH of phenol. In the presence of benzaldehyde, the conversion rate of phenol was below 10.0% with no cyclohexanone and cyclohexanol formation at 5 h. The density functional theory (DFT) calculations revealed that the phenol could promote the adsorption of benzaldehyde and facilitate the targeted conversion of benzaldehyde on the active site by lowering the reaction energy barrier. The research on the interaction between phenol and benzaldehyde in the ECH provides a theoretical basis for the application of ECH in practical bio-oil upgrading.