【摘要】 本文描述了流动态脉冲氢吸附装置用于Pt/γ-Al₂O₃催化剂的方法和技术。为了检测载气的纯度,在样品管进口直接连接装有变色的401型脱氧催化剂的检测管。通过条件试验,找到催化剂用量与脉冲体积的合适配比范围为4.8—10.0（克样/毫升脉冲）。测量了各种Pt/γ-Al₂O₃的氢吸附（以H/Pt表示）,计算得到的铂晶粒平均大小和电镜结果基本相符。由于净表面测出的各种Pt/γ-Al₂O₃的化学计量数比用氢吸附:氧吸附:氢滴定的比值表示,即HC:OC:HT为1:1:3,重复性较好,并且不随铂晶粒大小改变而改变。更多还原

【Abstract】 The procedure and technique for the determination of hydrogen chemi-sorption on Pt/r-Al2O3 catalyst by the flow type pulse adsorption method were described. A glass tube containing catalyst 401 which is used as a color indicator for trace amount of oxygen was connected with the sample tube to monitor the purity of carrier gas during operation. Experimental results showed that the optimum ratio of quantity of catalyst used to the volume of pulse was in the range of 2.4X10-2-5.0 X 10-2g(Pt)/ml(pulse). The hydrogen chemisorption (expressed as H/Pt) of various Pt/Al2O3 catalysts was measured,and the calculated mean size of platinum crystallites was in agreement with that directly electron microscopy-viewed. The stoi-chiometry of various Pt/Al2O3 expressed by ratio of hydrogen chemisorption: oxygen chemisorption:hydrogen tit ration (HC:OC:HT) is 1:1:3, which is reproducible and is invariant for catalysts with different mean size of platinum crystallite.更多还原