Selective chemical reduction of carbon dioxide to formate using microwave irradiation

• CO2 is selectively reduced to formate under microwave irradiation.
• The reduction process is fast (only 5 min).
• (NH4)2CO3 or dry ice were employed as CO2 precursors.
• NaBH4 was used as reducing agent.
• 1H, 13C and DEPT NMR spectra confirmed the production of formate from CO2.

Selective chemical reduction of carbon dioxide to formate anion under microwave irradiation is reported. No formaldehyde or methanol was generated as by products of the CO2 reduction making the process highly selective. (NH4)2CO3 or dry ice was employed as CO2 source. NaBH4 is used as reducing agent. Aqueous solutions of (NH4)2CO3 or dry ice and NaBH4 were subjected to microwave irradiation for a short duration of 5 min. The formation of formate is unequivocally established from the 1H, 13C and DEPT-135 NMR spectroscopic studies. FT-IR and UV–vis have been employed as auxiliary tools to observe the presence of formate ions. The obtained formate has the potential to be used as fuel in fuel cells or in turn can be converted to alkanes or can be used as a precursor for the production of hydrogen. Thus the current process is highly significant for the energy sector and to the chemical industry as well.

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