Synthesis and characterization of thermally stable mesostructured sulfated zirconia by a novel sulfate-assisted alcohothermal route

Abstract

Thermally stable mesostructured sulfated zirconia (MSZ) with a high surface area has been successfully prepared by a novel one-step synthetic method involving the alcohothermal processing of zirconium nitrate in the presence of ammonium sulfate. The MSZ samples were characterized using X-ray diffraction (XRD), N 2 adsorption measurements, thermal analysis (TG/DTA) and transmission electron microscopies (TEM). It is shown that the resulting mesostructured sulfated zirconia samples are tetragonal crystalline, which have a high specific surface area and a well-developed textural mesoporosity with narrow pore size distribution. Catalytic testing showed that the present mesostructured sulfated zirconia was much more active than conventional sulfated zirconia for n-butane isomerization.

酸化コバルトの酸性度に対する硫酸塩含浸法による硫酸化の影響

“…The content of SO4 2-as SO3 was determined from the results of the TG analysis. The weight decrease caused by the decomposition of sulfate ions was continuously observed up to 1273 K. The desorbed molecule in this stage was assumed to be SO3 12) 15) , and the sulfur content was calculated based on the weight change between 773 K and 1273 K. The weight change in the higher temperature range included desorption of oxygen. The conversion of Co3O4 to CoO was confirmed by XRD analysis.…”

“…The weight of Co3O4 was calculated assuming that the remaining material was pure CoO. The remaining weight, which involved subtracting that of O2 calculated from lost weight in the temperature range from 773 to 1273 K, was converted into the weight of SO3 decomposed 15) . The effect of heattreatment temperature on the content of SO3 was small on sulfated cobalt samples prepared by the impregna- The amount of sulfate ions on catalysts heat treated at 1273 K was the same in both preparation methods.…”

Simultaneous Al2O3 Doping and Sulfation in Hierarchically Porous ZrO2 Solid Acids by an One‐pot Synthesis for Enhanced Recycling Catalytic Performances

“…3 However, there are some critical problems of obtained SZ materials reported in literatures so far, such as poor stability in the presence of water because of the low crystallinity, quick loss of 2 4 SO -and tendency to undergo deactivation, which severely limit its practical applications. 4,5 Conventional methods of synthesizing SZ usually lead to lower surface area than 100 m 2 •g -1 , which is also one main reason for its low catalytic activity. So it is still a great challenge to develop efficient synthetic protocols to prepare SZ materials with well-defined structural characteristics and highly preserved 2 4 …”

Investigation of factors influencing catalytic activity for n-butane isomerization in the presence of hydrogen on Al-promoted sulfated zirconia

“…Generally, a larger surface area is required to reach a higher catalytic activity. Since conventional sulfated zirconia has a relatively small surface area, many methods have been attempted to improve its surface area [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. For example, sulfated zirconia was supported on silica materials and alumina materials with high surface area [30][31][32][33][34][35][36].…”

“…For example, sulfated zirconia was supported on silica materials and alumina materials with high surface area [30][31][32][33][34][35][36]. Mesostructured sulfated zirconia were synthesized using various templates [37][38][39][40], or by alcoholthermal route [41]. Nanosized [42][43][44] and macroporous [45] sulfated zirconia were also prepared.…”