Gold nanoparticles supported on MgOx-Al2O3 composite oxide: An efficient catalyst for selective hydrogenation of acetylene
Gold nanoparticles supported on MgOx-Al2O3 composite oxide: An efficient catalyst for selective hydrogenation of acetylene
复制标题
MgOx-Al2O3复合氧化物负载金纳米粒子：乙炔选择性加氢的高效催化剂
DOI：
10.1016/j.apsusc.2019.05.152
复制
发表时间：
2019
影响因子：
6.7
通讯作者：
Qi Caixia
中科院分区：
文献类型：
--
作者：
Sun Xun;Li Feifei;Shi Junjie;Zheng Yuhua;Su Huijuan;Sun Libo;Peng Shuang;Qi Caixia
负载型纳米金催化剂是一种高选择性的乙炔加氢催化剂，但活性低、积炭严重一直是金基催化剂的主要问题。采用改进的水化-煅烧工艺，制备了一系列从混合相到纯尖晶石结构的MgOx-Al 2 O3复合氧化物。由于其晶体缺陷和协同效应，550 °C处理的MgOx-Al 2 O3上的Au纳米颗粒（简称Au/3% MgOx-Al 2 O3 -550）具有较好的控制的较小粒径，从而提高了乙炔选择性加氢的活性。在250 °C下，转化率几乎是所有其他样品的两倍。H2-TPR和XPS结果表明，部分带正电荷的Au物种（Auδ+）在促进C三键C基团的吸附中起着至关重要的作用。程序升温氧化和拉曼光谱分析也表明，Au/3% MgOx-Al 2 O 3 -550比Au/Al 2 O 3具有更好的除焦效果。这份报告开辟了有前途的可能性工程的晶相的支持，高效的多相金催化剂。
Supported gold nanoparticles are highly selective catalysts for hydrogenation of acetylene, but low activity and heavy coke effect have been major concern for the Au-based catalysts. Based on a modified impregnation-calcination strategy, a series of MgOx-Al2O3composite oxides with different crystal structures from mixed phase to pure spinel was prepared. Due to its crystal defect and synergetic effect, Au nanoparticles on MgOx-Al2O3components treated at 550 °C (abbreviated as Au/3%MgOx-Al2O3-550) with well controlled smaller particle size gave an enhanced activity for the selective acetylene hydrogenation. The conversion rate was nearly twice as high as that of all other samples at 250 °C. The H2-TPR and XPS results indicate the partially positive charged Au species (Auδ+) played a crucial role in facilitating the adsorption of the Ctriple bondC group. Both the temperature programmed oxidation and Raman scattering also indicated that the Au/3%MgOx-Al2O3-550 showed better decoking effect than Au/Al2O3. This report opens up promising possibilities on engineering the crystal phase of support for the highly efficient heterogeneous gold catalysts.