Catalytic Hydrogenation of Aqueous Nitrate over Pd−Cu/ZrO2 Catalysts

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• 作者：Zhaoyi Xu ; Liqiang Chen ; Yun Shao ; Daqiang Yin ; Shourong Zheng
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2009
• 出版时间：September 16, 2009
• 年：2009
• 卷：48
• 期：18
• 页码：8356-8363
• 全文大小：282K
• 年卷期：v.48,no.18(September 16, 2009)
• ISSN：1520-5045

文摘

ZrO₂ supports with different properties were prepared, and the hydrogenation of aqueous nitrate catalyzed by ZrO₂ supported Pd−Cu bimetallic catalysts was investigated. The results showed that ZrO₂ support calcined at 573 K was unstable during the preparation of the bimetallic catalyst. Increasing calcination temperature led to the increase of particle size of ZrO₂ support. In addition, using ZrO₂ calcined at 973 K as the support resulted in the increase of metal particle sizes and the increased content of bimetallic ensembles at the expense of monometallic Pd. The bimetallic catalyst with ZrO₂ calcined at 773 K as the support exhibited higher catalytic activity and N₂ selectivity for the reduction of aqueous nitrate as compared to the bimetallic catalyst with ZrO₂ calcined at 573 or 973 K as the support. The activity and selectivity of ZrO₂ supported bimetallic catalysts for nitrate reduction also depended on the Pd/Cu ratio. Decreasing Pd/Cu ratio led to the decrease of the amount of monometallic Pd sites and to the increase of the content of Pd−Cu ensembles. The bimetallic catalyst with Pd/Cu ratio of 4/1 showed the optimum activity and N₂ selectivity for the reduction of aqueous nitrate.