A Carbon-Negative Hydrogen Production Strategy: CO₂ Selective Capture with H₂ Production

We reported a strategy of carbon-negative H₂ production in which CO₂ capture was coupled with H₂ evolution at ambient temperature and pressure. For this purpose, carbonate-type Cu_x Mg_y Fe_z layered double hydroxide (LDH) was preciously constructed, and then a photocatalysis reaction of interlayer CO₃ ^2- reduction with glycerol oxidation was performed as driving force to induce the electron storage on LDH layers. With the participation of pre-stored electrons, CO₂ was captured to recover interlayer CO₃ ^2- in presence of H₂ O, accompanied with equivalent H₂ production. During photocatalysis reaction, Cu_0.6 Mg_1.4 Fe₁ exhibited a decent CO evolution amount of 1.63 mmol g^-1 and dihydroxyacetone yield of 3.81 mmol g^-1 . In carbon-negative H₂ production process, it showed an exciting CO₂ capture quantity of 1.61 mmol g^-1 and H₂ yield of 1.44 mmol g^-1 . Besides, this system possessed stable operation capability under simulated flu gas condition with negligible performance loss, exhibiting application prospect.