CO2 reforming of methane over Ni/Mg/Al/Ce mixed oxides

Catalytic activity of hydrotalcite-derived catalysts in the dry reforming of methane: on the effect of Ce promotion and feed gas composition

“…T max was shifted from 810 to 835°C and from 780 to 820°C for HTNi25-Ce and HTNi5-Ce, respectively when compared to the unpromoted samples. These results are in good agreement with those reported in the literature [19][20][21]. The different trend for samples with or without Mg in its structure (HTNi100-Ce as compared to other catalysts) also suggests that the reducibility is an overlapping effect originating from the presence of both ceria and magnesium in the catalysts.…”

“…In this temperature region, the reduction process is quite complicated to explain since both processes of the reduction of NiO and ceria may have overlapped. The reduction of pure CeO 2 occurs in three stages: (i) the reduction of surface oxygen or oxygen capping species (250-300°C) [44], (ii) the reduction of surface lattice oxygen (450-600°C) [23] and total bulk reduction up to 900°C [21]. On the other hand, the reduction of Ni species from the framework of Mg(Ni,Al)O mixed oxides to metallic nickel is realized in two steps: (i) the reduction of surface NiO (ca.…”

“…To improve the stability of the Nibased catalysts, various promoters were proposed. Daza et al studied the promotion of Ni/Mg/Al hydrotalcite-derived materials with ceria [19][20][21][22][23] and showed that the final effect of Ce was influenced by the method of its introduction [21], loading (the optimal value was established to be ca. 3 wt% [19,20,23]), as well as hydrotalcite preparation method [22].…”

Ce - promoted catalyst from hydrotalcites for CO2 reforming of methane: calcination temperature effect

“…18,19 The catalysts were not previously reduced and reactants were injected from room temperature, increasing to 700 °C at 10 k min -1 . Flow of reactants used was CH 4 /CO 2 …”

“…[13][14][15] We have reported the use of different types of hydrotalcites and natural clays as catalyst precursors for CO 2 reforming of methane. [16][17][18][19][20][21][22] Specifically, in our work with hydrotalcites we have focused on the study of hydrotalcites of Ce-containing Ni-Mg-Al obtained by coprecipitation, 19,22 reconstruction 17,18 and self-combustion methods. 21 The work led to highly active catalysts that are both selective and stable, with strong basic properties, low particle sizes and low coke formation.…”