Promoting dry reforming of methane via bifunctional NiO/dolomite catalysts for production of hydrogen-rich syngas

Extensive effort has been focused on the advancement of an efficient catalyst for CO(2) reforming of CH(4) to achieve optimum catalytic activity together with cost-effectiveness and high resistance to catalyst deactivation. In this study, for the first time, a new catalytic support/catalyst system of bifunctional NiO/dolomite has been synthesized by a wet impregnation method using low-cost materials, and it shows unique performance in terms of amphoteric sites and self-reduction properties. The catalysts were loaded into a continuous micro-reactor equipped with an online GC-TCD system. The reaction was carried out with a gas mixture consisting of CH(4) and CO(2) in the ratio of 1 : 1 flowing 30 ml min(−1) at 800 °C for 10 h. The physicochemical properties of the synthesized catalysts were determined by various methods including X-ray diffraction (XRD), N(2) adsorption–desorption, H(2) temperature-programmed reduction (H(2)-TPR), temperature-programmed desorption of CO(2) (TPD-CO(2)), and temperature-programmed desorption of NH(3) (TPD-NH(3)). The highest catalytic performance of the DRM reaction was shown by the 10% NiO/dolomite catalyst (CH(4) & CO(2) conversion, χCH(4); χCO(2) ∼ 98% and H(2) selectivity, S(H(2)) = 75%; H(2)/CO ∼ 1 : 1 respectively). Bifunctional properties of amphoteric sites on the catalyst and self-reduction behaviour of the NiO/dolomite catalyst improved dry reforming of the CH(4) process by enhancing CH(4) and CO(2) conversion without involving a catalyst reduction step, and the catalyst was constantly active for more than 10 h.