Nano-sized ZrO2 derived from metal–organic frameworks and their catalytic performance for aromatic synthesis from syngas†,Catalysis Science & Technology

当前位置： X-MOL 学术 › Catal. Sci. Technol. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Nano-sized ZrO2 derived from metal–organic frameworks and their catalytic performance for aromatic synthesis from syngas†
Catalysis Science & Technology ( IF 4.4 ) Pub Date : 2019-04-23 00:00:00 , DOI: 10.1039/c9cy00453j
Jingge Liu _{1,

2,

3,

4,

5} , Yurong He _{1,

2,

3,

4,

5} , Linlin Yan _{1,

2,

3,

4,

5} , Ke Li _{1,

2,

3,

4,

5} , Chenghua Zhang _{1,

2,

3,

4,

5} , Hongwei Xiang _{1,

2,

3,

4,

5} , Xiaodong Wen _{1,

2,

3,

4,

5} , Yongwang Li _{1,

2,

3,

4,

5}

Affiliation

Oxide–zeolite bi-functional catalysts have shown promising potential in syngas aromatization. In the hydrogenation phase, the size effect of metal oxides needs to be researched. Herein, a series of tetragonal ZrO₂ with crystal sizes ranging between 4.0 and 11.3 nm was successfully prepared using UiO-66 as precursors, and it was found that the CO conversion and the methanol selectivity over ZrO₂ decreased, whereas the crystal size increased. After thorough characterization by X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, N₂ adsorption, pyridine-adsorbed infrared spectroscopy, temperature-programmed desorption of NH₃/CO/H₂, temperature-programmed reduction of H₂, X-ray photoelectron spectroscopy and electron paramagnetic resonance, we found that oxygen vacancies existed on the nano-sized ZrO₂ surface, which showed Lewis acidity, and the acid amount and the acid strength increased over the nano-sized ZrO₂ surface: the acid amount reached 345.62 μmol g⁻¹ with 9.26% strong acid sites over the minimum-sized ZrO₂. Density functional theory calculations were also carried out and the results demonstrated that the oxygen vacancies were beneficial for CO adsorption and activation; therefore, the minimum-sized ZrO₂ showed best CO conversion with abundant methanol produced. After physical mixing with H-ZSM-5, this bi-functional catalyst exhibited 11.67% CO conversion with the aromatics selectivity as high as 94.89% for C₅⁺. Furthermore, no obvious deactivation was observed during a 120 h stability test.

中文翻译：

源自金属-有机骨架的纳米级ZrO ₂及其对合成气芳烃合成的催化性能†

氧化物-沸石双功能催化剂在合成气芳构化方面显示出令人鼓舞的潜力。在氢化阶段，需要研究金属氧化物的尺寸效应。在此，以UiO-66为前驱体成功制备了一系列晶体尺寸在4.0〜11.3 nm的四方ZrO ₂，发现CO转化率和甲醇对ZrO _2的选择性降低，而晶体尺寸增加。通过X射线衍射，热重分析，透射电子显微镜，N彻底表征后₂吸附，吡啶吸附红外光谱，NH的程序升温脱附₃ / CO / H ₂，程序升温还原为h ₂中，X射线光电子能谱法和电子顺磁共振，我们发现纳米尺寸的ZrO上存在氧空位₂表面，其显示路易斯酸性，酸量和酸强度增加了纳米尺寸的ZrO ₂表面：在在最小尺寸的ZrO _2上，酸的量达到345.62μmolg ^-1，具有9.26％的强酸位。还进行了密度泛函理论计算，结果表明氧空位有利于CO的吸附和活化。因此，最小尺寸的ZrO ₂表现出最好的一氧化碳转化率，并产生大量甲醇。与H-ZSM-5物理混合后，该双官能催化剂显示出11.67％的CO转化率，对C ₅⁺的芳烃选择性高达94.89％。此外，在120小时的稳定性测试中未观察到明显的失活。

更新日期：2019-04-23

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南