The glycol solvent-thermal method prepared a serial of NiAlNd catalysts based on layered double hydrox-ides(LDHs)precursor.The introduction of Nd greatly promoted the catalytic activity for CO2 methanation at low temperatures.The CO2 conversion on the NiAlNd-0.4 catalyst reached 83.9％under the reaction condition:T=210 ℃,WHSV(weight hourly space velocity)=24 000 mL·g-1·h-1,p=100 kPa.The substitution of Nd3+for Al3+hin-dered the formation of LDHs structure in the precursor but decreased the particle size of the calcined catalyst.The interaction between NiO and Al2O3 was weakened with the introduction of Nd,resulting in better NiO component reducibility and high intrinsic activity of the Ni site.Moreover,the presence of Nd increased the number of surface basic sites of the catalyst,thus increasing the adsorption of CO2.With the increase in Nd,the surface area of metal-lic Ni in the reduced catalyst takes on a volcano-shape variation trend.The catalytic activities of NiAlNd catalysts are affected by the number and intrinsic activity of Ni sites simultaneously.
关键词
CO2甲烷化/层状双氢氧化物/NiAl催化剂/Nd/活性位
Key words
CO2 methanation/layered double hydroxide/NiAl catalyst/neodymium/active site
万方数据