Transfer hydrogenation of phenol on supported Pd catalysts using formic acid as an alternative hydrogen source
Transfer hydrogenation of phenol on supported Pd catalysts using formic acid as an alternative hydrogen source
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使用甲酸作为替代氢源在负载型 Pd 催化剂上转移氢化苯酚
DOI：
10.1016/j.cattod.2014.02.039
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发表时间：
2014-10-01
期刊：
影响因子：
5.3
通讯作者：
Wang, Yi Meng
中科院分区：
文献类型：
--
作者：
Zhang, Damin;Ye, Feiyang;Wang, Yi Meng
将粒径小于10 nm的钯纳米粒子负载在活性炭（AC）、MIL-101、TiO 2、Al 2 O3和TiO 2-活性炭复合物（TiO 2-AC）等载体上。这些催化剂在苯酚液相加氢反应中表现出较高的活性。还测试了它们在温和条件（T=50 ℃和P < 5 bar）下在苯酚与甲酸的转移加氢中的催化性能，以用于生物油的原位改质。催化剂的活性顺序为Pd/AC > Pd/TiO 2-AC > Pd/MIL-101 > Pd/TiO 2> Pd/Al 2 O3。当400 μ L甲酸被引入10 mL 0.25 M苯酚水溶液中时，在50 ℃下，在200 mg Pd/AC催化剂上，苯酚可以在4 h内完全氢化，环己酮的选择性为80%。Pd/AC催化剂的高氢转移活性使得生物油在温和条件下原位改质成为可能，将不稳定组分（如甲酸和苯酚）转化为稳定组分（主要是环己酮），然后将其引入现有炼油厂。此外，还报道了甲酸对负载型钯催化剂加氢活性的影响。甲酸的存在下，显着降低的Pd负载在MIL-101和氧化物（TiO 2和Al 2 O 3）的加氢活性，可能是由于竞争吸附的分子甲酸与苯酚上的一个单一的Pd网站。(C)2014爱思唯尔有限公司版权所有。
Palladium nanoparticles with size smaller than 10 nm were loaded on several supports including activated carbon (AC), MIL-101, TiO2, Al2O3, and TiO2-activated carbon composites (TiO2-AC). These catalysts showed high activity in liquid phase hydrogenation of phenol. Their catalytic performances in transfer hydrogenation of phenol with formic acid under mild conditions (T=50 degrees C and P < 5 bar) were also tested for the purpose of in situ upgrading of bio-oil. The activity followed the trend of Pd/AC > Pd/TiO2-AC > Pd/MIL-101 > Pd/TiO2 > Pd/Al2O3. When 400 mu L, of formic acid was introduced into 10 mL of 0.25 M aqueous phenol solution, phenol can be fully hydrogenated on 200 mg of Pd/AC catalyst at 50 degrees C within 4h, with 80% selectivity to cyclohexanone. The high activity of Pd/AC catalyst in hydrogen transfer makes it possible for in situ upgrading of bio-oil under mild conditions by converting unstable components (such as HCOOH and phenol) to stable ones (mainly cyclohexanone) which can then be potentially introduced into current refinery. In addition, the effect of formic acid on the hydrogenation activity of supported Pd catalysts was also reported. Presence of formic acid significantly decreased the hydrogenation activity of Pd supported on MIL-101 and oxides (TiO2 and Al2O3), probably due to the competitive adsorption of molecular formic acid with phenol on a single Pd site. (C) 2014 Elsevier B.V. All rights reserved.