Catalytic partial oxidation of methane to syngas: review of perovskite catalysts and membrane reactors

Abstract

Partial oxidation of methane (POM) offers a promising option to produce syngas for downstream processes such as hydrogen production and Fischer-Tropsch processes. POM in fixed-bed reactors requires an oxygen separation plant with high operation cost and safety risks.On the contrary, membrane reactors can provide an improved process by integrating both oxygen separation and catalytic reaction processes. With many advantages including high purity and efficient oxygen separation from the air at the catalytic reaction conditions, mixed ionic-electronic conducting membranes (MIEC) caught great attention in the scientific research field over the past two decades. In this review, POM using different catalysts in fixed-bed reactors was firstly summarised with emphasizing on perovskite-based catalysts, and then the material screening of MIEC membrane reactors was introduced and linked to the selection of conventional and perovskite catalysts. The catalytic activity, reaction mechanisms, and emerging challenges have been analyzed. Furthermore, future research directions have been outlined by highlighting the effect of electronic properties, continuous reduction-oxidation in the presence of oxygen flux, and chemical reaction mechanism on membrane/catalyst.

Core-Shell Fe2O3@La1−xSrxFeO3−δ Material for Catalytic Oxidations: Coverage of Iron Oxide Core, Oxygen Storage Capacity and Reactivity of Surface Oxygens

“…In heterogeneous oxidation catalysis, especially conducted in chemical looping mode using surface oxygens as active species for oxidative transformations of different substrates, application of core-shell materials may affect both the oxygen storage capacity and selectivity. For example, mixed oxides with perovskite structure are the most selective and highly regenerable catalysts for partial oxidation of methane to syngas [ 8 ] due to the proper states of oxygen ions on their surface [ 9 , 10 ]. However, they display relatively low oxygen storage capacity (OSC) of about 10 wt% compared with less active and less selective transition metal oxides such as Fe 2 O 3 (30 wt%) [ 11 , 12 ].…”

“…Preparation of thin continuous perovskite layers on iron oxide particles with a proper control of core surface coverage is challenging. Many studies were carried out for identification of surface oxygen species in mixed oxides including perovskites of different compositions and their reactions with catalytic substrates [ 8 , 9 , 10 , 28 , 29 , 30 ]. The effects of surface coverage of oxygen carriers on the oxidation state-distribution-redox reactivity of oxygen atoms at the surface of perovskite shell were not addressed.…”

Conversion of Methane with Oxygen to Produce Hydrogen Catalyzed by Triatomic Rh3– Cluster Anion

“…Contrary to the SRM reaction, the partial oxidation of methane (POM) that follows the reaction of CH 4 + O 2 → 2H 2 + CO 2 enables the generation of highly exothermic H 2 (Δ H 298 = −3.31 eV) and it is considered as a promising strategy to yield H 2 from an economical perspective. 6 , 7 However, limited by the inertness of CH 4 and O 2 molecules, the spontaneous POM reaction could occur only at high temperatures ( T > 700 °C) in the absence of a catalyst. 8 Since the first experimental detection of free H 2 from POM reaction catalyzed by Ni/Al 2 O 3 in 1929, 9 various heterogeneous catalysts supported with base and precious metals have been engineered for CH 4 conversion at relatively low temperatures.…”

Computational Fluid Dynamics Modeling to Simulate a Combined Reforming Process for Syngas and Hydrogen Production

“…Non-catalytic POX can occur with methane, heavy oil, and coal at 1,150-1,315°C, whereas catalytic POX can occur at a lower temperature of 950°C with methane and naphtha (Steinberg and Cheng 1989). In non-catalytic POX, the syngas produced has a very high temperature at 1,200-1,400°C and high impurities resulting from the heavy hydrocarbon feedstocks that must be cleaned and cooled (Elbadawi et al 2021). Texaco and Shell developed a non-catalytic POX that resulted in a high syngas yield at high temperatures and pressures (Pen et al, 1996).…”