论文部分内容阅读
将溶剂法用于测定深色的加氢裂化和加氢处理催化剂的表面酸量及酸强度分布,并且用氨吸附-差热分析法进行了对照实验,发现两者有类似的酸强度分布曲线。用溶剂法考察了活性金属氧化物对催化剂酸性的影响,发现某些活性金属氧化物如NiO和WO_3自身没有强酸部位,却具有使无定形硅铝或含分子筛的酸性载体强酸量增加的能力。对照进行的吡啶吸附-红外光谱实验结果表明,活性金属氧化物使催化剂表面的Brosted酸量发生了与溶剂法所测得的强酸量有一定的相关关系的变化;用溶剂法测定了酸性组份(超稳Y型分子筛)含量不同的载体以及用这些载体制成的Ni-W催化剂的强酸量,发现溶剂法对试样酸性的变化反应灵敏。当载体含有45％(质量)超稳Y型分子筛时,加入Ni-W活性组份能使其强酸部位的增量达到最大。
The solvent method was used to determine the surface acidity and acid strength distribution of the dark hydrocracking and hydrotreating catalysts. A control experiment was conducted using ammonia adsorption-differential thermal analysis and found to have similar acid strength distribution curves . Solvent method was used to investigate the effect of active metal oxide on the acidity of the catalyst. Some active metal oxides such as NiO and WO_3 were found to have no strong acid sites themselves, but their ability to increase the acidity of amorphous silica-alumina or acidic support with molecular sieve was found. The experimental results of pyridine adsorption-infrared spectroscopy showed that the amount of Brosted acid on the surface of catalyst increased with the amount of strong acid measured by the solvent method. The content of acid in the acidic component (Ultra-stable Y-type molecular sieves), and the amount of strong acid on Ni-W catalysts prepared from these supports, the solvent method was found to be sensitive to changes in the acidity of the sample. When the support contains 45% (mass) of ultra-stable Y-type molecular sieve, the addition of Ni-W active component can maximize the increment of strong acid sites.