Effect of metal amount on the catalytic performance of Ni–Al2O3 catalyst for the Tri-reforming of methane

• Published in: International journal of hydrogen energy 2023-02, Vol.48 (14), p.5478-5492
• Main Authors: Gupta, Satyam, Deo, Goutam
• Format: Article
• Language: English
• Subjects: CO2 conversion; Nickel loading; Reduction temperature; Synthesis gas; Tri-reforming of methane
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.11.049

Mesoporous Ni–Al2O3 catalysts with Ni weight (%) 5 to 15 were synthesized, characterized, and tested for tri-reforming of methane (TRM). The characterization results reveal that the metal loading influences the metal-support interaction of the catalysts. Furthermore, the choice of reduction temperature affected the dispersion of metallic-Ni. It is advantageous to reduce these catalysts at their respective Tmax temperatures, which are obtained from H2-TPR studies. At these conditions, the dispersion was maximum. For TRM at 600 °C, the conversions and yields increased with an increase in Ni loading, and carbon was not detected. Increasing the metal loading from 5 wt% to 15 wt% increased the CH4 conversion from 70.5 to 82.4% and CO2 conversion from 10.2 to 19.7%. In contrast, the H2/CO ratio decreased from 3.8 to 3.2. The conversions and yields during TRM were relatively constant with time-on-stream and were highest for 15Ni–Al. Furthermore, H2/CO ratio was >3, and minimal change in dispersion was observed post-reaction for this catalyst. Thus, the active metal loading and the reduction temperature required are important parameters that need to be considered while designing a suitable catalyst for TRM. [Display omitted] •Ni amount and reduction temperature strongly affect the Ni crystallite size.•Catalytic performance depends on dispersion, and significant conversions achieved.•H2/CO ratio >3 and no carbon deposited during TRM at 600 °C for all loadings.•Reduction at Tmax provides best catalytic performance; Tmax is obtained by H2-TPR.•15Ni–Al shows highest catalytic activity and minimal change in Ni size post-reaction.