Palladium supported on bacterial biomass as a novel heterogeneous catalyst: A comparison of Pd/Al2O3 and bio-Pd in the hydrogenation of 2-pentyne
Palladium supported on bacterial biomass as a novel heterogeneous catalyst: A comparison of Pd/Al2O3 and bio-Pd in the hydrogenation of 2-pentyne
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DOI：
10.1016/j.ces.2009.06.069
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发表时间：
2010-01-01
影响因子：
4.7
通讯作者：
Wood, J.
中科院分区：
文献类型：
--
作者：
Bennett, J. A.;Creamer, N. J.;Wood, J.
在搅拌釜反应器中测试了负载在细菌生物质上的钯纳米颗粒bio-Pd在2-戊炔氢化中的催化活性。在各种反应条件下，将使用新材料获得的反应速率和选择性与用常规非均相催化剂钯/氧化铝获得的那些进行比较。在相同的条件下，在异丙醇中的5wt%的生物Pd催化剂上的反应的初始速率仅为5wt%Pd/Al 2 O3催化剂的30%。然而，生物质负载的显示出高的选择性，在5小时后显示出定量的炔转化率，其中戊烯/戊烷的最大产物比在8-14的范围内，顺式/反式产物比在6-14的范围内。尽管常规的5%Pd/Al 2 O3催化剂得到非常高的初始戊烯/戊烷和顺式/反式比率（26和10），但这些值在反应过程中迅速下降，并且在大于70%的炔转化率下变得略低于用生物Pd观察到的值。例如，在92%的炔转化率下，生物-Pd催化剂给出2.5的顺式/反式比率和3.3的戊烯/戊烷比率，而5%Pd/Al 2 O3的相应值为2.0和2.0。这是第一次在多产物反应中证明了生物Pd的选择性，从而显示了这种材料用于催化合成的前景，其中希望最大化特定组分的产率。在2-戊炔氢化实验中用作支持物的细菌类型是脱硫脱硫弧菌。金属颗粒在电池外壳内生长，规则地分散，并且具有均匀的颗粒尺寸，如通过化学吸附测定的类似于1.7nm。生物Pd也容易从产物混合物中分离，并且当在随后的氢化中重复使用时保持活性和选择性。(C)2009爱思唯尔有限公司保留所有权利。
Nanoparticles of palladium supported on bacterial biomass, bio-Pd, were tested for their catalytic activity in the hydrogenation of 2-pentyne in a stirred tank reactor. The rates of reaction and the selectivity obtained using the novel materials were compared to those obtained with a conventional heterogeneous catalyst, palladium on alumina, under various reaction conditions. Under the same conditions, the initial rate of reaction over a 5 wt% bio-Pd catalyst in isopropanol was only 30% of that for a 5 wt% Pd/Al2O3 catalyst. However, the biomass-supported showed a high selectivity, displaying quantitative conversions of alkyne after 5 h with maximum product ratios of pentene/pentane in the range of 8-14 and cis/trans product ratios in the range of 6-14. Although the conventional 5% Pd/Al2O3 catalyst gave very high initial pentene/pentane and cis/trans ratios (26 and 10), these values fell rapidly over the course of the reaction and became slightly lower than those observed with bio-Pd at alkyne conversions greater than 70%. For example, at 92% alkyne conversion, the bio-Pd catalyst gave a cis/trans ratio of 2.5 and pentene/pentane ratio of 3.3, as opposed to respective values of 2.0 and 2.0 with 5% Pd/Al2O3. This is the first time that selectivity has been demonstrated for the bio-Pd in a multi-product reaction, thus showing promise of this material for use in catalytic syntheses where it is desirable to maximise yield of a specific component. The type of bacteria used as support in the 2-pentyne hydrogenation experiments was Desulfovibrio desulfuricans. The metal particles grow within the cell envelope, are regularly dispersed and are of uniform particle size, of similar to 1.7 nm as determined by chemisorption. The bio-Pd is also easily separated from the product mixture and remained active and selective when reused in a subsequent hydrogenation. (C) 2009 Elsevier Ltd. All rights reserved.