• 关键词：液相催化加氢脱溴  4-溴苯酚  Pd/Al₂O₃  碳包覆催化剂

• 基金项目：国家重点研发计划（No.2020YFC1807003）；国家自然科学基金（No.21577056 ）

• 邓东芝
• 南京大学环境学院，污染控制与资源化研究国家重点实验室，南京 210046

• 孙敬雅
• 南京大学环境学院，污染控制与资源化研究国家重点实验室，南京 210046

• 郑寿荣
• 南京大学环境学院，污染控制与资源化研究国家重点实验室，南京 210046

• 摘要：在污染物液相催化加氢脱卤过程中，提高催化剂的稳定性至关重要.以水热合成法制备了不同碳包覆量的Pd/Al₂O₃@C催化剂，对催化剂进行了系列表征，并将催化剂应用于4-溴苯酚（4-BP）污染物的催化加氢脱溴反应.表征结果显示碳层提高了Pd/Al₂O₃的表面疏水性，有利于4-BP在催化剂上的吸附.并且在Pd/Al₂O₃@C催化剂的碳化过程中，碳还原部分Pd颗粒，并保留部分正价态Pd活性位，增强了4-BP中C-Br键的活化.与Pd/Al₂O₃相比，碳涂层提高了催化剂的催化活性.但当碳包覆量超过最佳包覆量后，暴露的Pd粒子随碳包覆量的增加而减少，导致活性下降.此外，碳层修饰后，催化剂的稳定性显著提高，从而大大抑制了Pd粒子的团聚和损耗.Pd/Al₂O₃@C表面的碳涂层对卤素具有较高的耐受性，从而减轻了液相催化加氢脱卤反应中活性中心的中毒.

• Abstract：Exploring efficient and stable catalysts is of crucial importance for the aqueous catalytic hydrodehalogenation of pollutants. Herein， we prepared the Pd/Al₂O₃@C catalysts with varied carbon-encapsulation amounts by a hydrothermal approach. The catalysts were characterized and applied for the catalytic hydrodebromination of 4-bromophenol （4-BP）. The carbon coating layer improves surface hydrophobicity of Pd/Al₂O₃@C， favoring 4-BP adsorption on the catalyst. During the carbonization of Pd/Al₂O₃@C， carbon partially reduces Pd particles with positively charged Pd sites residual， enhancing the activation of C-Br bonds in 4-BP. In comparison with Pd/Al₂O₃， carbon coating enhances the catalytic activity of Pd/Al₂O₃； while excessive carbon coating， substantially decrease Pd particle，and thus decreased catalytic activity. Besides， carbon coating remarkedly promoted the stability of Pd/Al₂O₃ and greatly suppressed the agglomeration and loss of Pd particles. Additionally， Pd/Al₂O₃@C has exhibited high tolerance towards halogens and thus alleviated the poisoning of active centers during the aqueous catalytic hydrodehalogenation reaction.

• Key words：liquid phase catalytic hydrodebromination  4-bromophenol  Pd/Al₂O₃  carbon coated catalysts

• 
  摘要点击次数： 201 全文下载次数： 260