Comparative Studies of Non‐noble Metal Modified Mesoporous M‐Ni‐CaO‐ZrO₂ (M = Fe, Co, Cu) Catalysts for Simulated Biogas Dry Reforming

Abstract

The present work is aimed to improve the performance of Ni‐based catalysts for biogas dry reforming by adding a second non‐noble metal (Fe, Co, Cu) into a previously studied mesoporous Ni‐CaO‐ZrO2 nanocomposite. Biogas was simulated with equivalent methane and carbon dioxide for the dry reforming reaction. X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), N2 adsorption, temperature‐programmed reduction (TPR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) measurements were taken to characterize the structural and textual properties of the bimetallic catalysts as well as the accumulated carbon deposition. The addition of Fe leads to a less ordering growth of mesopores of Fe‐Ni‐CaO‐ZrO2 sample, and the existence of Cu results in a relatively larger portion of free NiO in Cu‐Ni‐CaO‐ZrO2. Compared with Fe and Cu, the presence of Co could efficiently form a beneficial dual metal effect and enhance the strong metal support interaction between Ni and CaO‐ZrO2, thus enhancing the activity and stability of the catalyst in biogas dry reforming reaction.

Bimetallic Synergy Effects of Phyllosilicate‐Derived NiCu@SiO2 Catalysts for 1,4‐Butynediol Direct Hydrogenation to 1,4‐Butanediol

“…[26] Besides, the reduction peak areas of the above two stages showed regular variation trends with the alteration of Ni/Cu content in the bimetallic NiCuphy@SiO 2 . [22,[33][34][35] Predictably, as labeled in Figure 2b, some ill-crystallized nickel phyllosilicate phase was still present for all the Ni containing NiCu@SiO 2 . We believe this new formed metal species is responsible for the highly active Ni species that differentiated from the Niphy matrix by the induction of promoting Cu species.…”

“…This shift is interpreted by the generation of defective sites in the metallic Ni phase via the addition of Cu species, thus resulting in the formation of a homogeneous NiÀ Cu intermetallic mixture/alloy in the phyllosilicate-derived catalyst system, similar conclusion was also reported for other bimetallic catalysts. [22,[33][34][35] Predictably, as labeled in Figure 2b, some ill-crystallized nickel phyllosilicate phase was still present for all the Ni containing NiCu@SiO 2 . This phenomenon is in accordance with the H 2 -TPR results that a reduction temperature of 500°C cannot reduce all the Niphy phase.…”

Ordered mesoporous Fe-Al2O3 based-catalysts synthesized via a direct "one-pot" method for the dry reforming of a model biogas mixture

“…Carbon content exceeded 12 wt% over a mesoporous Ni modified by tungsten Ni 5% W 5% Al 2 O 3 catalyst even when operated under less drastic biogas reforming conditions (inlet molar feed CH 4 /CO 2 ¼ 1:1) [73]. Similarly, for an equimolar gaseous inlet feed, carbon contents exceeded 15 wt% over spent mesoporous Ni-Fe (Co or Cu)-CaO-ZrO 2 catalysts [74]. For a biogas reforming operation (CH 4 /CO 2 ¼ 1.5) close to that adopted in this study, a Ni 8% Al 2 O 3 catalyst prepared via standard post-impregnation over commercial alumina support displayed a 7 wt% C (s) content after a short exposure to reaction medium [25].…”

Hydrogen Production From Biogas Reforming: An Overview of Steam Reforming, Dry Reforming, Dual Reforming, and Tri-Reforming of Methane

“…4.10 Influence of the reaction pressure on the equilibrium of an equimolar mixture of CH 4 and CO 2 at 700°C. modification of supports and addition of promoters has become a main focus area in many studies (Wang et al, 2017;Qian et al, 2014;Zarei et al, 2016;Djinovi c and Pintar, 2017). The recent efforts in designing promoted and supported nonnoble metal catalysts for DRM are comprehensively discussed in this section.…”