Safe and efficient catalytic reaction for direct synthesis of CO from methylcyclohexane and CO2

The reverse water gas shift (RWGS) reaction is one kind of the catalytic conversion of CO 2 to reduce an enormous amount of CO 2 . However, the RWGS reaction has the safety hazards associated with the use of hydrogen and thermodynamic limitation. Therefore, this work proposes a new safe and efficient reaction route (CO 2 -MCH) to get CO from CO 2 and methylcyclohexane (MCH). Thermodynamic calculations showed that the equilibrium CO 2 conversion at 350 °C increased from 17.8 % of the RWGS reaction to 53.5 % of the CO 2 -MCH reaction. In the CO 2 -MCH reaction, the relationship of the catalytic performance with the metal dispersion, the Pt particle size and the acidity of Pt-based catalysts on the different supports was investigated, respectively. The results showed that the Pt/γ-Al 2 O 3 catalyst with high dispersion of Pt particles, small particle size and medium acidity had good activity and selectivity. The relationships among Pt loading and Pt particle size on the Pt/γ-Al 2 O 3 catalyst and the catalytic performance were evaluated. The Pt particle size gradually increased with the metal loading. A positive correlation was observed between Pt particle size and CO 2 conversion; a volcano-type relationship was observed between CO selectivity and Pt particle size. In the CO 2 -MCH reaction at 350 °C, 0.1 MPa, LHSV = 6 h −1 , the CO 2 conversion was 24.7 %, the CO selectivity reached 95.2 %, and the Pt/γ-Al 2 O 3 catalyst within 40 h showed good stability. Moreover, the mechanism of the CO 2 -MCH catalytic reaction over the Pt/γ-Al 2 O 3 catalyst was speculated.