Palladium catalyst samples were prepared upon bacterial biomass supports (Gram-positive A. oxidans and Gram-negative R. capsulatus) and tested in the partial hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol. The objectives of the study were to assess the effects of operating conditions in the stirred autoclave upon the reaction conversion and selectivity and to compare the biologically supported palladium (BioPd) catalyst performance with that of a conventionally supported catalyst. Variables investigated included solvent, stirring speed, and catalyst metal loading. A maximum selectivity toward 2-butene-1,4-diol of 0.98 was observed in a solvent composed of 5% isopropyl alcohol (2-propanol) in water at a conversion of 75% 2-butyne-1,4-diol for the Pd/A. oxidans catalyst. The Pd/R.capsulatas catalyst showed a maximum selectivity of 1.0 at a conversion of 62.6%. Concentration profiles of the different hydrogenation products were fitted using a Langmuir−Hinshelwood expression, which showed a higher fitted adsorption constant of 2-butyne-1,4-diol in a 5% 2-propanol/water solvent, compared with pure 2-propanol, suggesting that adsorption is stronger in the mixed solvent. At a typical catalyst loading of 0.29 g/L (Pd/R. capsulatus), analysis of the mass-transfer steps in the reactor showed that ∼63% of the resistance to mass transfer lies at the catalyst (liquid−solid) particle and ∼37% lies at the gas bubble interface. BioPd was proven to be a highly selective catalyst for partial hydrogenation reactions and has the advantage that it can be prepared inexpensively from metal-waste-bearing solutions.

中文翻译：

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使用新型生物钯催化剂加氢2-丁炔-1,4-二醇

钯催化剂样品在细菌生物质载体（革兰氏阳性制备A. oxidans和革兰氏阴性R.荚膜）和2-丁炔-1,4-二醇的部分氢化进行测试，以2-丁烯-1,4-二醇。该研究的目的是评估搅拌高压釜中操作条件对反应转化率和选择性的影响，并将生物负载的钯（BioPd）催化剂的性能与常规负载的催化剂进行比较。研究的变量包括溶剂，搅拌速度和催化剂金属负载量。在由5％异丙醇（2-丙醇）组成的溶剂中，对于2-丁烯-1,4-二醇的转化率为75％，观察到的对2-丁烯-1,4-二醇的最大选择性为0.98。 Pd / A.氧化酶催化剂。Pd /荚膜R.荚膜催化剂显示最大选择性为1.0，转化率为62.6％。使用Langmuir-Hinshelwood表达式拟合不同氢化产物的浓度曲线，与纯2-丙醇相比，该表达式显示在5％2-丙醇/水溶剂中2-丁炔-1,4-二醇的较高拟合吸附常数，表明在混合溶剂中吸附更强。在0.29 g / L（Pd / R。荚膜），对反应器中传质步骤的分析表明，约63％的传质阻力位于催化剂（液体-固体）颗粒上，约37％处于气泡界面处。事实证明，BioPd是用于部分氢化反应的高度选择性催化剂，其优点是可以廉价地从含金属废物的溶液中制备。