pH值对沉淀法制备Cu2(OH)3Cl-CuO超细粉体催化活性的影响

超细粒子因其具有明显的体积效应和表面效应，在催化、功能材料等领域得到了广泛的应用［１～３］，这在一定程度上促进了其制备科学的发展。超细粒子的制备方法较多，通常分为物理法、化学法和综合法三大类。其中化学沉淀法是一种最经济、最常用的制备超细氧化物粉体的方法。目前，采用沉淀法制取ＣｕＯ系列催化剂多以Ｃｕ（ＮＯ３）２ 为原料，而以其它二价铜盐为原料来考察制备条件对所得粉体催化活性影响的研究报道尚少［４，５］。为此，我们以ＣｕＣｌ２ 为原料，采用沉淀法制备ＣｕＯ 催化剂，结果意外地得到了一种对分解Ｈ２Ｏ２ 具有极高催化活性的Ｃｕ２（ＯＨ）３Ｃｌ－ＣｕＯ超细粉体，并发现反应液ｐＨ 值是控制该粉体物相、粒子大小及催化活性的关键。此结果为Ｃｕ 系催化剂的研究、开发，特别是对Ｏ２ 电极催化材料的制备提供了有价值的信息

EFFECT OF pH VALUE ON THE CATALYTIC ACTIVITY OF Cu2(OH)3Cl-CuO ULTRAFINE POWDER PREPARATION BY PRECIPITATION METHOD

The title ultrafine powders were prepared by chemical precipitation, using CuCl₂ as raw material. The effect of the pH value of reaction solution on the phase, grain size, morphology and catalytic act-ivity of ultrafine pow-ders for H₂O₂ decomposition were investigated by the means of XRD and TEM. The experiment results show that with the increase of pH value from 7 to 14, the phase of the powders changes from simple Cu₂(OH)₃Cl to Cu₂(OH)₃Cl and CuO then to pure CuO and the catalytic activity of the powders versus pH passes through a maxinum at the pH=8.5, at which the grain size is about 15 nm and the powder exhibits the highest surface area and activity among the samples studies.