Activated LiBH4 and Ni/LiBH4-assisted CO2 hydrogenation to C1, C2 products at low temperature

Abstract

We found that the activated LiBH₄ or Ni/LiBH₄ can effectively assist CO₂ hydrogenation into C1 and C2 products at low temperature (100–300 ℃). After CO₂ hydrogenation over the activated LiBH₄ or Ni/LiBH₄, CH₄ with approximately 100 % selectivity was formed in the gas phase products. CH₃OH, HCOO⁻, and high-value CH₃CH₂OH were observed in aqueous solution of spent LiBH₄ or Ni/LiBH₄ after CO₂ hydrogenation. CO₂ conversion and CH₄ production are able to be further improved by doping 5–20 wt% Ni into the activated LiBH₄. The LiBH₄ sample shows a 61.34 % CO₂ conversion at 200 ℃, while the 20 %Ni/LiBH₄ composite displays an 80.14 % CO₂ conversion under the same conditions. The experimental and theoretical results suggest that the synergistic effect from Ni and LiBH₄ results in high CO₂ conversion at low temperature. This new method for CO₂ conversion to C1, C2 products using the activated Ni/LiBH₄ composite may enlighten the materials design for CO₂ utilization.