Simultaneously converting carbonate/bicarbonate and biomass to value-added carboxylic acid salts by aqueous-phase hydrogen transfer

A novel approach to coproduce value-added carboxylic acids has been developed via a 'one-pot' aqueous-phase hydrogen transfer (APHT) process, in which hydrogen in biomass molecules is transferred to carbonate/bicarbonate ions over supported noble metal nanocatalysts. In mild hydrothermal media, a variety of biomass derived alcohols or polyols have been efficiently converted to carboxylic acids, while simultaneously, formates have been obtained from the reduction of carbonates/bicarbonate salts without using external H₂. In an APHT process at the optimized reaction conditions, a high yield of lactate, ∼55%, was achieved using glycerol as the hydrogen donor, and simultaneously, ∼30% of formate was produced by the reduction of sodium bicarbonates over the Pd on a carbon catalyst. The catalyst was stable after three-time consecutive reuse without regeneration, and the possible APHT reaction mechanism was proposed.