Syngas electrosynthesis using self-supplied CO2 from photoelectrocatalytic pollutant degradation

Syngas has been synthesized via (photo) electrochemical CO 2 reduction. Its amount and yield efficiency are determined the utilizable CO 2 . Here we show syngas electrosynthesis using self-supplied CO 2 , namely in situ generated CO 2 from photoelectrocatalytic pollutant oxidation. In a single-chamber based two-electrode system, CO 2 is produced continuously during photoelectrocatalytic phenol oxidization on the anode of TiO 2 nanotubes decorated with Pd nanoparticles. Such in-situ generated CO 2 is then reduced into CO at a Pd-Cu cathode. With a phenol oxidation efficiency of 87% and a faradaic efficiency of 75%, the syngas yield is as high as 339.3 μmol. The ratio of carbon-to-hydrogen in syngas is variable from 0 to 1:10 under different current densities. The reactions for syngas generation are investigated using in-situ electrochemical infrared technique and confirmed to be C 6 H 5 OH→CO 2 →CO 2 *→COOH*→CO*+H + →CO+H 2 . This study thus provides an approach to degrade pollutants and simultaneously utilize produced CO 2 for the production of value-added chemicals like syngas.