Progresses in the Preparation of Coke Resistant Ni‐based Catalyst for Steam and CO₂ Reforming of Methane

Abstract

Steam reforming of methane is an extremely important process for the hydrogen and syngas production. Nickel‐based catalysts have been extensively employed in the industrial process of steam reforming because of their high activity, low cost, and the plentiful supply of Nickel. Nickel‐based catalysts have also shown high activity for CO2 reforming of methane, which has been considered as a good option, with consumption of a significant amount of carbon dioxide. However, a major challenge is that Ni catalysts have a high thermodynamic potential for coke formation during reforming reactions. For steam reforming, coke formation induces deactivation of the catalyst, especially if the carbon forms as carbon filaments. The filamentous carbon material has a high mechanical strength and can cause mechanical deformation of the catalyst. For CO2 reforming, coke formation over Ni catalyst is even more serious and leads to rapid deactivation of the catalyst. It is highly desired to design and synthesize a coke resistant Ni catalyst not only for reforming of methane, but also for reforming of other hydrocarbons (including biomass derived hydrocarbons). Herein we summarize the very recent progresses in the design, synthesis, and characterization of coke resistant Ni catalysts for steam and CO2 reforming of methane. The progresses in the use of promoters, in the effect of supporting materials and in the preparation methods have been discussed. The thermal stability, regeneration, and future development of coke resistant Ni catalysts for these processes are also briefly addressed.

OXIDATIVE-REFORMING OF METHANE AND PARTIAL OXIDATION OF METHANE REACTIONS OVER NiO/PrO2/ZrO2 CATALYSTS: EFFECT OF NICKEL CONTENT

“…On the other hand, the properties of PrO2 such as oxygen storage capacity, oxygen vacancies and redox (owing to the oxidation states Pr 3+ /Pr 4+ ) are well known and documented (Liu et al, 2011). Pr has been used as a promoter of Ni based catalysts for various reforming reactions, as described by Gallego et al 2009) for perovskite (Ni/La/O) derived catalysts; by Gamba et al (2011) for Ni catalysts supported on smectite, and by Barroso et al (2011) for Ni catalysts supported on MgAl2O4.…”

Relationship between carbon morphology and catalyst deactivation in the catalytic decomposition of biogas using Ni, Co and Fe based catalysts

“…Catalyst particles encapsulation by carbon is considered one of the main causes of deactivation in process in which hydrocarbons are decomposed [2,49]. In steam and dry reforming of methane, it is generally accepted that different kinds of carbon are formed during reaction [49][50][51][52], so it is likely that the same structures are formed in the CDB: high reactive carbon (C α or atomic carbon), amorphous carbon (C β ), and graphitic carbon (C γ ).…”

“…Biogas, mainly composed by CH 4 and CO 2 , is obtained by anaerobic digestion of biodegradable wastes. Its composition makes biogas an interesting feedstock for the dry reforming of methane (DRM) process (CH 4 +CO 2 ↔ 2H 2 + 2CO, ∆Hº= 247 kJ·mol -1 ).…”

“…DRM has been extensively studied over different catalysts [1] and research efforts are aimed to synthesize an active and H 2 selective catalyst that minimizes surface carbon accumulation in order to avoid catalyst deactivation [2]. It is well known that noble metal catalysts meet those requirements [3,4].…”

Nickel catalyst supported on magnesium and zinc aluminates (MgAl2O4 and ZnAl2O4) spinels for dry reforming of methane

“…In last years, much effort has been devoted to the development of Ni base catalysts with improved performance, i.e. less deposition of coke and increased metal stability against sintering [21][22][23]. To inhibit deactivation of nickel catalysts many researchers have investigated the support effect in the carbon deposition [23][24][25][26][27].…”