制备方法对B2O3/ZrO2催化剂结构的影响

采用XRD和TG—DTA技术对以未晶化的Zr(OH)4和已晶化的ZrOz作载体的B202／ZrO2催化剂进行了研究，考察了载体预焙烧温度、催化剂焙烧温度和B202含量对催化剂体相结构、活性组分存在状态的影响，讨论了活性组分B202对载体发生晶相变化时的作用。结果表明，在Zr(OH)4上的H3BO3使载体在焙烧时晶粒生长受阻，对载体发生的相变有明显的延迟作用；负载B203的样品在活化焙烧过程中脱水变得困难；B203含量的增加使催化剂中的ZrO2单斜晶相比例增加。

THE EFFECT OF PREPARATION METHOD ON THE STRUCTURE OF B2O3/ZrO2 CATALYSTS

The B2O3/Zr/O2 catalysts with the support of amorphous Zr(OH)4 and crystallized ZrO2 were studied by means of XRD and TG-DTA techniques. The effect of pre-calcination tempera- ture of support, the calcination temperature for the catalyst, and the level of boria on catalyst structure and the forms of active component boria on the phase transformation of zirconia support was discussed. The results showed that the crystallite growth of the hydrous zirconia precursor was retarded during calcination and an accompanying phase transformation of support was obviously delayed by the incorporation of boric acid. The water in samples supported on boria was evaporated hardly during the catalyst activation calcination. The monoclinic phase of catalysts also increased with B2O3 load increasing.