Abstract:

Exploring effective nano-Au loading mechanism can improve the loading capacity, stability and distribution anchoring effect of Au nanoparticles (NPs), so as to construct the high-performance catalytic reaction system. The amino functionalized polymer template method was adopted to fabricate the Au@H-mCeO₂ hollow core-shell composite catalyst with the mCeO₂ mesoporous shell and encapsulated nanosized Au active sites. Due to the excellent oxygen overflow property of mCeO₂ and the enhanced synergistic effect between Au and mCeO₂, the catalyst showed significantly better catalytic performance than mTiO₂ and mSiO₂ shell deposited catalysts in the solvent-free selective catalytic oxidation of benzyl alcohol into benzaldehyde. Under the optimal reaction conditions, the conversion of benzyl alcohol catalyzed by Au@H-mCeO₂ catalyst reached 60% and the selectivity of benzaldehyde was 88%. The recombination process of in-situ supported Au NPs assisted by amino functionalized polymer template and mesoporous oxide encapsulation of mCeO₂ can better disperse and stabilize the catalytic active sites of Au NPs. Thus, in the cyclic reaction and thermal filtration experiments, the aggregation and loss of Au NPs can be effectively inhibited, so that the excellent catalytic reaction activity and stability of the catalyst can be maintained.

Key words: catalyst, core-shell structure, template method, oxidation, benzyl alcohol

摘要：

探索纳米Au高效固载机制有助于提高Au纳米粒子负载能力、稳定性及分布位置锚定效果，从而构建高性能催化反应体系。采用氨基功能化聚合物模板法构建mCeO₂介孔壳层封装纳米Au活性位的Au@H-mCeO₂核壳中空复合催化剂。mCeO₂优异的氧溢出性能及Au与mCeO₂增强性协同作用，使得该催化剂在无溶剂条件下选择性催化氧化苯甲醇制得苯甲醛反应中，表现出明显优于mTiO₂和mSiO₂壳层催化剂的催化性能。最佳反应条件下，Au@H-mCeO₂催化剂催化氧化苯甲醇转化率为60%，制得的苯甲醛选择性为88%。氨基功能化聚合物模板导向的原位固载Au纳米颗粒与mCeO₂介孔氧化物封装构筑的复合过程，有助于分散和稳定纳米Au催化活性位，有效抑制其在循环反应和热过滤实验中可能出现的聚集和流失，从而保持较好的催化反应活性和稳定性。

关键词: 催化剂, 核壳结构, 模板法, 氧化, 苯甲醇