Surface functionalized highly porous date seed derived activated carbon and MoS₂ nanocomposites for hydrogenation of CO₂ into formic acid

In recent years, substantial progress has been made towards developing effective catalysts for the hydrogenation of CO₂ into fuels. However, the quest for a robust catalyst with high activity and stability still remains challenging. In this study, we present a cost-effective catalyst composed of MoS₂ nanosheets and functionalized porous date seed-derived activated carbon (f-DSAC) for hydrogenation of CO₂ into formic acid (FA). As-fabricated MoS₂/f-DSAC catalysts were characterized by FE-SEM, XRD, Raman, FT-IR, BET, and CO₂-TPD analyses. At first, bicarbonate (HCO₃^–) was successfully converted into FA with a high yield of 88% at 200 °C for 180 min under 10 bar H₂ atmosphere. A possible reaction pathway for the conversion of HCO₃^– into FA is postulated. The catalyst has demonstrated high activity and long-term stability over five consecutive cycles. Additionally, MoS₂/f-DSAC catalyst was effectively used for the conversion of gaseous CO₂ into FA at 200 °C under 20 bar (CO₂/H₂ = 1:1) over 15 h. The catalyst exhibited a remarkable TOF of 510 h^–1 with very low activation energy of 12 kJ mol⁻¹, thus enhancing the catalytic conversion rate of CO₂ into FA. Thus, this work demonstrates the MoS₂/f-DSAC nanohybrid system as an efficient non-noble catalyst for converting CO₂ into fuels.