羟基磷灰石负载Ni催化剂中Ni含量对催化甲烷二氧化碳重整制合成气性能的影响

以低温沉淀方法制备的羟基磷灰石(HAp)为载体,采用浸渍法制备了一系列不同Ni含量的Ni/HAp催化剂,并采用BET、H2-TPR、XRD、SEM、FT-IR、TEM和TG-DTA技术对催化剂进行了表征。结果表明,NiO含量为13%的催化剂表现出最好的催化甲烷二氧化碳重整制合成气活性,在850℃、空速3.6×104mL/(h·gcat)的反应条件下,甲烷和二氧化碳的转化率在10 h内分别稳定在72%和83%。这主要归因于催化剂中金属和载体之间的强相互作用。虽然反应后的催化剂表面有少量的积炭,但这些积炭多以丝状炭存在,并不会影响催化剂的活性和稳定性。

Effects of Ni content of Ni/hydroxyapatite catalysts on catalytic properties for carbon dioxide reforming of methane

Carbon dioxide reforming of methane to synthesis gas was investigated with a series of Ni catalysts supported on Hydroxyapatite (HAp) prepared by chemical precipitation at low temperature. The structure and properties of the catalysts were characterized using BET, H₂-TPR, XRD, SEM, FT-IR , TEM and TG-DTA techniques. The 13% NiO/HAp showed the highest activity for catalytic carbon dioxide reforming of methane to synthesis gas. Under the condition of an atmospheric pressure at 850 ℃ and a gas hour space velocity (GHSV) of 3.6 ×10⁴ mL/(h·g_cat), the conversion of CH₄ and CO₂ over 13% Ni/HAp catalyst remained almost constant, at about 72% and 83%, for 10 h, respectively, which was ascribed to strong metal-support interaction. Most of the carbonaceous deposits on the catalyst surface were in whisker form, which did not cover the active sites and then had limited influence on the catalyst activity and stability.