Hydrothermal Reduction of CO2 to Value-Added Products by In Situ Generated Metal Hydrides

Abstract

An integrated process by coupling hydrothermal reactions, including CO2 reduction and H2O dissociation with metals, is proposed. The hydrogen could be rapidly produced under hydrothermal conditions, owing to the special characteristics of high temperature water, generating metal hydrides as intermediates. Hydrogen production from the H2O dissociation under hydrothermal conditions is one of the most ideal processes due to its environmentally friendly impact. Recent experimental and theoretical studies on the hydrothermal reduction of CO2 to value-added products by in situ generated metal hydrides are introduced, including the production of formic acid, methanol, methane, and long-chain hydrocarbons. These results indicate that this process holds promise in respect to the conversion of CO2 to useful chemicals and fuels, and for hydrogen storage, which could help alleviate the problems of climate change and energy shortage.

Synthesis, structure and luminescence of two europium complexes of diphenylimidazophenanthrolines

“…17,18 For [Eu 2 (papip) 2 (PhCH 2 COO) 6 ], these signals disappear, whereas two weak bands emerge at 3380 and 3318 cm −1 , ascribable to the asymmetric and symmetric stretch of the primary amino group. 19 To the best of our knowledge, the -NO 2 to -NH 2 conversion has not been reported yet in any hydrothermal condition, although the hydrothermal reduction has already been established for some other substances, like carbon CrystEngComm Paper dioxide, 20 graphene oxide, 21 and copper(II). 22,23 For the analogous compound 2-(4-nitrophenyl)imidazo[4,5-f ][1,10] phenanthroline, the transformation of -NO 2 to -NH 2 was ever observed to occur in presence of reductants hydrazine hydrate 24,25 or Na 2 S. 26 We have conducted a series of hydrothermal reactions employing pnpip and any one or two of three other reactants mentioned before, Eu(NO 3 ) 3 •6H 2 O, NaOH and phenylacetonitrile, or ammonia (which should be another product of hydrolysis of phenylacetonitrile), but the nitro peaks always remained in the infrared spectra of the corresponding products.…”