CuMnOS Nanoflowers with Different Cu+/Cu2+ Ratios for the CO2-to-CH3OH and the CH3OH-to-H2 Redox Reactions

Abstract 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 Cu Mn OS nanoflower catalysts. The [Cu + ]-high Cu Mn OS led to a CH 3 OH yield of 21.1 mmol·g −1 catal.·h −1 in the Cu Mn OS-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 Cu Mn OS-CH 3 OH-H 2 O system. The successful redox reactions at NTP rely on active lattice oxygen of Cu Mn OS 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.