:
Hydrogenation of CO2 to energy-rich products over heterogeneous metal catalysts has
gained much attention due to their commercial applications. Specifically, the first-row transition metal
catalysts are very rarely reported and discussed for the production of formic acid from the hydrogenation
of CO2. Herein, hydrotalcite supported copper metal has shown activity and efficiency to produce
formic acid from the hydrogenation of CO2, without adding any additional base or promoter and was
effectively recycled 4 times after separating by simple filtration without compromising the formic acid
yield. Hydrotalcite supported copper-based catalyst (Cu-HT) was synthesized through the coprecipitation
method and used as a heterogeneous catalyst for the hydrogenation of CO2. The precise
copper metal content determined by ICP in Cu-HT is 0.00944 mmol. The catalyst afforded maximum
TOF, 124 h-1 under the employed reaction conditions: 100 mg catalyst, 60 °C, 60 bar total pressure of
CO2/H2 (1:1, p/p) with 60 mL of mixed methanol:water (5:1, v/v) solvent. Cu-HT catalyst was synthesised
and thoroughly characterized by FT-IR, PXRD, SEM, TEM, XPS and BET surface area. The
first-order kinetic dependence with respect to the catalyst amount, partial pressures of CO2, and of H2
was observed and a plausible reaction mechanism is suggested.
Background:
CO2 hydrogenation to energy-rich products over heterogeneous metal catalysts has
gained much attention due to their commercial applications. Specifically, the first-row transition metal
catalysts are very rarely reported and discussed for the production of formic acid from the hydrogenation
of CO2.
Objective:
he aim is to investigate the heterogeneous catalyst systems, using solid soft base hydrotalcite
supported Cu metal-based catalyst for effective and selective hydrogenation of CO2 to formic
acid.
Methods:
The Cu –HT catalyst was synthesized and characterized by FT-IR, PXRD, SEM, TEM, XPS
and BET surface area in which the precise copper content was 0.00944 mmol. The Cu-HT catalysed
hydrogenation of CO2 was carried out in the autoclave.
Results:
The Cu-HT catalyst afforded maximum TOF of 124 h-1 under the employed reaction conditions:
100 mg catalyst, 60 °C, 60 bar total pressure of CO2/H2 (1:1, p/p) with 60 mL of mixed methanol: water
(5:1, v/v) solvent, without adding any additional base or promoter and was recycled 4 times by simple
filtration without compromising the formic acid yield. Formation of formic acid was observed to depend
on the amount of the catalyst, partial pressures of CO2 and H2, total pressure, temperature and time.
Conclusion:
Cu-HT based heterogeneous catalyst was found to be efficient for selective hydrogenation of
CO2 to formic acid and was effectively recycled four times after elegantly separating by simple filtration.
Synthesis, Characterization, and Application of Poly(N,N′-dibromo-N-ethylnaphthyl-2,7-disulfonamide) as an Efficient Reagent for the Synthesis of 2-Arylbenzimidazole and 2-Aryl-1-arylmethyl-1H-1,3-benzimidazole Derivatives
