Nickel-Based Ceria, Zirconia, and Ceria–Zirconia Catalytic Systems for Low-Temperature Carbon Dioxide Reforming of Methane

Abstract

Carbon dioxide reforming of methane (CDRM) was studied over a variety of ZrO 2 -, ceria-doped ZrO 2 -, and CeO 2 -ZrO 2 -supported Ni catalysts. Different techniques were used to prepare supports material having different physicochemical properties, and a correlation was established to show the importance of a robust support material. Various characterization of the catalyst further established that the coking behavior of the catalyst depends on the support preparation techniques. Compared to zirconia and ceria-doped zirconia, the use of ceria-zirconia (Ce x Zr 1-x O 2 ) solid solution as a support prepared by using a surfactant was found to be the most stable for low-temperature CDRM. It seems the inhibition of reactions leading to carbon deposition is prominent in systems having ZrO 2 . Temperature-programmed oxidation (TPO) experiments indicated excellent resistance toward carbon formation for Ni supported on Ce x Zr 1-x O 2 compared with other catalysts studied. H 2 -TPR (temperature-programmed reduction) analyses also showed that the stability of Ce x Zr 1-x O 2 solid solution is a function of its enhanced reducibility at lower temperatures as compared to either pure ceria or ceria-doped ZrO 2 . Based on all the catalysts studied, 5% Ni Ce 0.6 Zr 0.4 O 2 was found to be the best catalyst as activity was stable for up to 100 h at 650 and 700 °C, while at 800 °C the catalyst activity remained stable for more than 200 h.

Enhanced Catalytic Activity of Supported Gold Catalysts for Oxidation of Noxious Environmental Pollutant CO

“…Therefore, the observed shift in 2 positions is the outcome of successful substitution of Ce 4+ ions with isovalent Zr 4+ . This also confirms the formation of CZ solid solutions [22,23]. This incident is quite reinforced by the fact that CZ has smaller crystallite size than pure CeO 2 (obtained from Scherrer equation) as can be seen from the values given in Table 1 [7,24].…”

The Effect of WO3 Modification of ZrO2 Support on the Ni-Catalyzed Dry Reforming of Biogas Reaction for Syngas Production

“…In this respect, nickel based catalysts attract particular attention as they are known to exhibit excellent catalytic performance; the drawback is that they suffer from the aforementioned problems Charisiou et al, 2016b;Elsayed et al, 2017). In theory, coke deposition can be avoided by: (i) altering the electronic properties of metal-support interactions, (ii) influencing the size of metallic particles and, (iii) improving the oxygen storage capacity and mobility within supporting material (Roh et al, 2006;Kumar et al, 2007;Chen et al, 2008;Goula et al, 2014;Yentekakis et al, 2015Yentekakis et al, , 2016Han et al, 2017). Thus, the attempts that have been undertaken to improve the stability of DRM nickel catalysts have focused on the use of different oxides as supports (e.g., Al 2 O 3 , SiO 2 , La 2 O 3 , CeO 2 , ZrO 2 ) (Pompeo et al, 2007;Bereketidou and Goula, 2012;Li et al, 2016) or the use of a variety of dopants that include transition metals (e.g., Fe, Co, Sn) (Ay and Uner, 2015;Theofanidis et al, 2015;Zhao et al, 2016), noble metals (e.g., Ag, Pt, Pd, Ir) Yentekakis et al, 2015;Yu et al, 2015), lanthanide metals (e.g., La, Ce, Pr) (Goula et al, 2016a;Vasiliades et al, 2016;Xiang et al, 2016) and alkaline earth metals (e.g., Sr, Ca, Ba) (Bellido et al, 2009;Sutthiumporn and Kawi, 2011).…”

Methanol steam reforming behavior of copper impregnated over CeO 2 –ZrO 2 derived from a surfactant assisted coprecipitation route

“…A similar study on a commercial MSR catalyst by Choi and Stenger has shown a good on stream reactivity pattern at a very low space velocity of 1100 h -1 [4]. In another study, Kumar et al have carried out the CO2 reforming reaction of CH4 over 5% Ni impregnated on surfactant (CTAB) assisted coprecipitation synthesized Ce0.60Zr0.40O2 showing better the catalytic stability than the corresponding normal coprecipitation prepared sample [39]. In other word, the catalytic activity of the materials is highly sensitive to the synthesis procedure adopted.…”

“…The latter method has drawn considerable interest due to the high surface area and Though the CO formation can take place either via reverse WGS reaction or via methanol decomposition, most studies have reported its formation exclusively through the former reaction [4,7e9]. Peppley et al suggested that the major improved thermal stability of the resulting materials [39].…”