A highly stable Pd/SiO2/cordierite monolith catalyst for 2-ethyl-anthraquinone hydrogenation
A highly stable Pd/SiO2/cordierite monolith catalyst for 2-ethyl-anthraquinone hydrogenation
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DOI：
10.1039/c5ra17285c
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发表时间：
2015-11
期刊：
影响因子：
3.9
通讯作者：
Xiaotong Li;Hongjiu Su;Gaoyuan Ren;Shudong Wang
中科院分区：
文献类型：
--
作者：
Xiaotong Li;Hongjiu Su;Gaoyuan Ren;Shudong Wang
乙基蒽醌（EAQ）加氢制备环境友好氧化剂H2 O2时，催化剂的稳定性是急需解决的问题。本文采用浸渍法制备了高稳定性的蛋壳型Pd/SiO2/堇青石整体式催化剂（PSC）。为了比较，还制备了Pd/Al 2 O3/堇青石整体式催化剂（PAC）。催化剂的稳定性测试在连续滴流床反应器中在40 °C下以25 h-1的高液体空速进行。结果表明，PSC催化剂在1000 h内具有稳定的H2 O2产率，而PAC催化剂在100 h内失活。采用X射线衍射（XRD）、N2吸附、NH3程序升温脱附（NH3-TPD）、傅里叶变换红外光谱（FTIR）、扫描电镜（SEM）、透射电镜（TEM）、H2程序升温还原（H2-TPR）和X射线光电子能谱（XPS）等手段对催化剂进行了表征。N2吸附和NH3-TPD结果表明，PSC催化剂具有规则的结构和很弱的酸性，这有助于提高催化剂的选择性和稳定性。较低的载体焙烧温度有利于提高Pd的分散度和降低Pd的损失，有利于提高催化剂的加氢效率。
Catalyst stability is an urgent issue for ethyl-anthraquinone (EAQ) hydrogenation to produce the environment friendly oxidant H2O2. Herein, a highly stable egg-shell Pd/SiO2/cordierite monolith catalyst (PSC) was prepared by an impregnation method. For comparison, a Pd/Al2O3/cordierite monolithic catalyst (PAC) was also prepared. The stability tests of the catalysts were conducted in a continuous trickle bed reactor at 40 °C with a high liquid space velocity of 25 h−1. It turned out that the PSC catalyst obtained a stable H2O2 yield in the 1000 h test while the PAC catalyst deactivated in 100 h. The as-prepared catalysts were characterized by X-ray diffraction (XRD), N2 adsorption, NH3 temperature programmed desorption (NH3-TPD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), H2 temperature programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). N2 adsorption and NH3-TPD results showed that the PSC catalyst had a regular structure and very weak acidity, which contributed to improving the catalyst selectivity and stability. Besides, the lower support calcination temperature was found to be beneficial to improving the hydrogenation efficiency because of higher Pd dispersion and lower Pd loss.