Yttrium promoted Ni-based double-layered hydroxides for dry methane reforming

Abstract

Yttrium modified Ni-based double-layered hydroxides were tested as novel catalysts in dry methane reforming. The catalysts were characterized by XRF, BET analysis, XRD, TPR-H 2 , TPD-CO 2 , TGA/DSC-MS, H 2 chemisorption and TEM. Co-precipitation with yttrium (III) nitrate hexahydrate resulted in increased specific surface area, smaller Ni crystallite size, enhanced reducibility, and higher distribution of weak and medium basic sites as compared to Y-free material. The DRM catalytic tests, carried out in the temperature range of 850-600 ºC, led to a significant improvement of activity, with the 1.5 wt % Y-promoted catalyst being the most efficient in converting both CH 4 and CO 2. Moreover, the 10 h test at 700 ºC further confirmed enhanced stability for this HTNi-Y1.5 catalyst. Higher CO 2 conversion than CH 4 conversion and less CO compared to H 2 proves that side reactions are occurring simultaneously.

Highly Carbon-Resistant Y Doped NiO–ZrOm Catalysts for Dry Reforming of Methane

“…While for the NiO-ZrOm-YOn catalyst, it decreases from 16 nm to 10 nm after reaction for 8 h, which indicates the re-dispersion of Ni 0 . Similar phenomenon had been reported by other researches [37,38,42]. Nakayam et al [43] found the redispersion of Ni under an alternating condition between H2 reduction and oxidation atmosphere.…”

“…Thus, one can note that the addition of yttrium modifies both the distribution and the number of basic sites. A similar phenomenon can be observed in our group's previous works [37,40]. According to the literature [10,38,39], the weak and medium-strength basic sites can promote the formation of activation carbonate species, thereby enhancing the ability to remove the carbon deposition.…”

“…The total number of basic sites increases from 73 to 100 µmol CO 2 /g on the NiO-ZrO m catalyst before and after the introducing of yttrium (see in Table 2), which indicates that the yttrium can enhance the total number of basic sites. As already described elsewhere [37][38][39], there are three types of basic sites (weak, medium-strength and strong). The content of weak peak on the NiO-ZrO m -YO n catalyst (36.9%) is higher than that on the NiO-ZrO m catalyst (15.5%), while the content of the strong peak decreases to 13.0% on the NiO-ZrO m -YO n catalyst.…”

Ce- and Y-Modified Double-Layered Hydroxides as Catalysts for Dry Reforming of Methane: On the Effect of Yttrium Promotion

“…Dry reforming of methane (DRM) is considered as a promising technology of CO 2 utilization by CH 4 . The process results in synthesis gas production, and the latter can be converted into important chemicals, such as methanol or long chain hydrocarbons, e.g., diesel [1,2].…”

“…From thermodynamics, it is well known that DRM starts to be favorable at ca. 700 • C [3,4]. While the operational conditions impose some challenges, there is still lack of a proper catalyst for such process in terms of reactivity and stability.…”