Nickel–alumina cryogel was prepared from aluminium sec-butoxide and nickel acetate by one-pot sol–gel processing and subsequent freeze drying. Catalysis for CO₂ reforming of CH₄ and carbon formation during the reforming were examined on the cryogel by comparison to those on the corresponding xerogel catalyst prepared by employing normal drying in order to evaluate the utility of the freeze drying. While the catalytic activity was not different significantly between the two sol–gel catalysts, carbon formation was suppressed more markedly on the cryogel than on the xerogel. The surface area and pore volume of the catalyst after the calcination and after the subsequent high-temperature reduction were larger for the cryogel than for the xerogel. XRD, UV-visible, FT-IR, and Raman spectra suggested the principal formation of NiAl₂O₄ after the calcination for both catalysts, whereas the presence of NiO, leading finally to large nickel particle, was suggested for the xerogel although it may be a small portion. Mean diameter of nickel particles estimated from TEM and XRD showed smaller size for the cryogel than for the xerogel. These results suggested that role of the freeze drying was to improve structural and textual properties of alumina gel as well as to give finer nickel particles throughout the gel.

镍-氧化铝冷冻凝胶是由仲丁醇铝和乙酸镍通过一锅法溶胶-凝胶加工和随后的冷冻干燥制得的。CH _4的CO ₂重整催化通过与通过正常干燥制备的相应干凝胶催化剂上的那些进行比较，在冷冻凝胶上检查了重整过程中的重整率和碳的形成，以评估冷冻干燥的效用。尽管两种溶胶-凝胶催化剂之间的催化活性没有显着差异，但在低温凝胶上比在干凝胶上，碳的形成受到的抑制更为明显。煅烧后和随后的高温还原后，催化剂的表面积和孔体积比干凝胶大。XRD，紫外可见，FT-IR和拉曼光谱表明NiAl ₂ O ₄的主要形成两种催化剂都经过煅烧后，尽管存在的NiO可能很小，但仍建议将其用于干凝胶。根据TEM和XRD估算的镍颗粒平均直径显示，冻干凝胶的粒径小于干凝胶的粒径。这些结果表明，冷冻干燥的作用是改善氧化铝凝胶的结构和质地，并在整个凝胶中产生更细的镍颗粒。