Hydroxymethylsulfonate (HMS) is an important cleaning agent in the electronics industry and serves as a crucial intermediate in the synthesis of surfactants and pharmaceuticals. Conventional industrial production of HMS relies on toxic and volatile formaldehyde, presenting considerable safety and environmental risks. Herein, we report a solar-driven photocatalytic route for the synthesis of HMS from waste SO2 and polyethylene terephthalate (PET)-derived ethylene glycol (EG) under ambient conditions, using a Cu single-atom-decorated TiO2 catalyst (Cu1/TiO2). The optimized Cu1/TiO2 catalyst achieves an HMS yield rate of ∼ 2.31 mmol gcat -1 h-1 with a 77.5% carbon selectivity, along with a H2 evolution rate of ∼ 4.36 mmol gcat -1 h-1. Mechanistic studies reveal that the atomically dispersed Cu sites act as electron sinks, which enhance charge separation and induce electronic modulation of TiO2. This modulation facilitates the adsorption and activation of reactants while lowering the energy barrier for the formation of a key *CHOH─CH2OH intermediate via EG dehydrogenation. This resulting intermediate then undergoes nucleophilic attack by hole-generated •SO3 -, triggering C─C cleavage to form HMS. This work establishes a sustainable and waste-valorizing route for organosulfur synthesis.
Liang et al. (Tue,) studied this question.