This review will explore the influences of the active metal, support, promoter, preparation methods, calcination temperature, reducing environment, particle size and reactor choice on catalytic activity and carbon deposition for the dry reforming of methane Bimetallic (Ni−Pt, Ni−Rh, Ni−Ce, Ni−Mo, Ni−Co) and monometallic (Ni) catalysts are preferred for dry reforming compared to noble metals (Rh, Ru and Pt) due to their low-cost Investigation of support materials indicated that ceria−zirconia mixtures, ZrO2 with alkali metals (Mg2+, Ca2+, Y2+) addition, MgO, SBA-15, ZSM-5, CeO2, BaTiO3 and Ca08Sr02TiO3 showed improved catalytic activities and decreased carbon deposition The modifying effects of cerium (Ce), magnesium (Mg) and yttrium (Y) were significant for dry reforming of methane MgO, CeO2 and La2O3 promoters for metal catalysts supported on mesoporous materials had the highest catalyst stability among all the other promoters Preparation methods played an important role in the synthesis of smaller particle size and higher dispersion of active metals Calcination temperature and treatment duration imparted significant changes to the morphology of catalysts as evident by XRD, TPR and XPS Catalyst reduction in different environments (H2, He, H2/He, O2/He, H2−N2 and CH4/O2) indicated that probably the mixture of reducing agents will lead to enhanced catalytic activities Smaller particle size (

Dry reforming of methane: Influence of process parameters—A review

Progress in oxygen carrier development of methane-based chemical-looping reforming: A review

The abrupt and massive deactivation of methane dry reforming catalysts especially Ni-based is still a monumental impediment towards its industrialization and commercialization for production of value-added syngas via Fischer-Tropsch process. The need for further and more critical understanding of inherent and tailored interactions of catalyst components for performance and stability enhancement during reforming reaction cannot be over-emphasized. This review provides a contemporary assessment of progresses recorded on synergistic interplay among catalyst components (active metals, support, promoters and binders) during dry reforming using state-of-the-art experimental and theoretical techniques. Advancements achieved during interplay leading to improvements in properties of existing catalysts and discovery of novel ones were stated and expatiated. Reaction pathways, catalytic activities, selection of appropriate synthesis route and metal/support deactivation via sintering or carbon deposition have over time been successfully studied and explained using information from these crucial component interactions. This perspective describes the roles of these interactions and their applications towards development of robust catalysts configurations for successful industrial applications.

A review on catalyst development for dry reforming of methane to syngas: Recent advances

Overview of hydrogen production technologies from biogas and the applications in fuel cells

Chemical looping offers a versatile platform to convert fuels and oxidizers in a clean and efficient manner. Central to this technology are metal oxide materials that can oxidize fuels, affording a reduced material that can be reoxidized to close the loop. Recent years have seen substantial advances in the design, formulation and manufacture of these oxygen carrier materials and their incorporation into chemical looping reactors for the production of various chemicals. This Review describes the mechanisms by which oxygen carriers undergo redox reactions and how these carriers can be incorporated into robust chemical looping reactors. One promising technology for modern energy and chemical conversions is chemical looping, central to which are redox cycles of metal oxides. This Review describes chemical looping schemes and the mechanisms by which metal oxide particles enable these technologies.

Metal oxide redox chemistry for chemical looping processes

Chemical-looping reforming of methane (CLRM) offers an effective approach for coproducing syngas and pure hydrogen. In this work, CeO2 nano particles (2–3 nm) are well dispersed on the wall surface of three-dimensional ordered macroporous (3DOM) LaFeO3, obtaining a highly efficient oxygen carrier for the CLRM technology. The physical and chemical properties of the oxygen carriers were characterized by SEM, TEM, H2-TPR, XPS, XRD, CH4-TPR and CH4-TPD techniques. It is found that the presence of CeO2 on LaFeO3 results in the formation of Ce3+ and Fe2+ due to the CeO2-LaFeO3 interaction. The coexistence of Ce3+ and Fe2+ irons induces abundant oxygen vacancies on the mixed oxides, which strongly improves the reducibility, oxygen mobility and reactivity for methane oxidation. The presence of CeO2 also improves the resistance towards carbon deposition formation, and this allows the CeO2/LaFeO3 materials own high available oxygen storage capacity (available OSC, the maximum amount of oxygen consumed by methane reduction without the formation of carbon deposition). It is also noted that the agglomeration of CeO2 nano particles would reduce the reactivity of oxygen carriers. Among all the obtained samples, the 10% CeO2/LaFeO3 sample exhibits the highest yields of syngas (9.94 mmol g−1) and pure hydrogen (3.38 mmol g−1) without the formation of carbon deposition, which are much higher than that over the pure LaFeO3 sample (5.73 mmol g−1 for syngas yield and 2.00 mmol g−1 for hydrogen yield). In addition, the CeO2/LaFeO3 oxygen carrier also showed high stability during the successive CLRM testing either in the activity (yields of syngas and pure hydrogen) or structure (macroporous frameworks) aspect.

Designed oxygen carriers from macroporous LaFeO3 supported CeO2 for chemical-looping reforming of methane

Ce–Fe oxygen carriers for chemical-looping steam methane reforming

Chemical-looping steam methane reforming (CL-SMR) is a promising method for the co-generation of pure hydrogen and syngas on the basis of redox cycles via a gas–solid reaction using an oxygen carrier. The performance and life of the oxygen carrier play pivotal roles in determining the feasibility and economy of the CL-SMR process. The present research was focused on the evolution of the structure and reducibility of a CeO2–Fe2O3 oxygen carrier during the CL-SMR redox process to further understand the sustainability of the oxygen carrier. The investigated CeO2–Fe2O3 complex oxide exhibited satisfactory performance in the CL-SMR process because of the chemical interaction between Ce and Fe species. A Ce–Fe–O phase equilibrium based on a stable composition of CeO2, Fe3O4, and CeFeO3 formed in the recycled samples. Surface oxygen was removed, which was accompanied by an increase in the concentration of oxygen vacancies and a decrease in the surface area of the recycled samples; these effects resulted in an in...

Chemical-Looping Steam Methane Reforming over a CeO2–Fe2O3 Oxygen Carrier: Evolution of Its Structure and Reducibility

Structure dependence and reaction mechanism of CO oxidation: A model study on macroporous CeO2 and CeO2-ZrO2 catalysts

Chemical looping technology enables achievement of the simultaneous feedstock conversion and product separation without additional processes via circulating solid intermediates (so-called oxygen/ni...

Xing Zhu

Papers

Designed oxygen carriers from macroporous LaFeO3 supported CeO2 for chemical-looping reforming of methane

Ce–Fe oxygen carriers for chemical-looping steam methane reforming

Chemical-Looping Steam Methane Reforming over a CeO2–Fe2O3 Oxygen Carrier: Evolution of Its Structure and Reducibility

Structure dependence and reaction mechanism of CO oxidation: A model study on macroporous CeO2 and CeO2-ZrO2 catalysts

Chemical Looping Conversion of Gaseous and Liquid Fuels for Chemical Production: A Review