CuMnOS Nanoflowers with Different Cu(+)/Cu(2+) Ratios for the CO(2)-to-CH(3)OH and the CH(3)OH-to-H(2) Redox Reactions

A conservative CO(2)-Methanol (CH(3)OH) regeneration cycle, to capture and reutilize the greenhouse gas of CO(2) by aqueous hydrogenation for industry-useful CH(3)OH and to convert aqueous CH(3)OH solution by dehydrogenation for the clean energy of hydrogen (H(2)), is demonstrated at normal temperature and pressure (NTP) with two kinds of CuMnOS nanoflower catalysts. The [Cu(+)]-high CuMnOS led to a CH(3)OH yield of 21.1 mmol·g(−1)catal.·h(−1) in the CuMnOS-CO(2)-H(2)O system and the other [Cu(+)]-low one had a H(2) yield of 7.65 mmol·g(−1)catal.·h(−1) in the CuMnOS-CH(3)OH-H(2)O system. The successful redox reactions at NTP rely on active lattice oxygen of CuMnOS catalysts and its charge (hole or electron) transfer ability between Cu(+) and Cu(2+). The CO(2)-hydrogenated CH(3)OH in aqueous solution is not only a fuel but also an ideal liquid hydrogen storage system for transportation application.