Combined steam and dry reforming of methane for syngas production from biogas using bimodal pore catalysts

Three catalysts with bimodal pore structure: Ni/Al2O3, Ni/MgO-Al2O3, Ni/La2O3-Al2O3 were prepared by refluxed co-precipitation method and characterized by N-2 adsorption-desorption, XRD, TPR, H-2-TPD and CO2-TPD. For comparison, a Ni catalyst impregnated on commercial alumina was also prepared. The catalysts were tested in combined steam and dry reforming of methane (CSDRM) at atmospheric pressure, 600-700 degrees C and CH4: CO2:H2O = 1:0.48:0.8, for the preparation of synthesis gas with H-2:CO ratio proper for methanol synthesis. The presence of both magnesium and lanthanum oxides contributes to a better dispersion and stabilization of Ni nanoparticles on the catalyst surface. The catalytic activity for CSDRM increases in the order Ni/Al2O3(r) < Ni/Al2O3 < Ni/La2O3-Al2O3 approximate to Ni/MgO-Al2O3. TPD methods revealed that the good performance of Ni/La2O3-Al2O3 is a consequence of its good properties for hydrogen adsorption, while the improved catalytic properties of Ni/ MgO-Al2O3 reside in its good properties for CO2 adsorption. Synthesis gas with the H-2:CO ratio between 2.3 and 2.5 was obtained for all the reaction conditions used in this work. The bimodal pore catalysts showed no deactivation during 6 h TOS. The analysis of used catalysts established the catalyst with the best stability as being Ni/La2O3-Al2O3.

Automated summary

Three catalysts with bimodal pore structure, Ni/Al2O3, Ni/MgO-Al2O3, Ni/La2O3-Al2O3, were prepared and tested for combined steam and dry reforming of methane. Both magnesium and lanthanum oxides contributed to better dispersion and stabilization of Ni nanoparticles on the catalyst surface. Ni/La2O3-Al2O3 showed the best stability and catalytic activity among the tested catalysts.