Self-Promoted H 2 Formation: The Feasibility of Photoinduced CO Removal for Lossless Hydrogen Purification.

A photoinduced radical reaction operated at low temperature can be used to remove trace CO from a H 2 stream by minimizing the reverse water-gas shift. However, H 2 consumption resulting from nonselective oxidation by hydroxyl radicals becomes an obstacle to practical hydrogen purification. Inspired by hydrogen exchange transfer, we demonstrate here that molecular hydrogen can promote H 2 formation from hydrogen radicals, which are generated from the reaction of CO and H 2 with hydroxyl radicals. The slight increment in H 2 along with the radical reaction encouraged us to configure a photocatalytic hydrogen purification fixed-bed reactor, which can reduce CO to ≤1 ppm in the H 2 stream.