Solid-phase Hydrogenation of Organic Compounds over Metal Catalysts

以富马酸二钠和顺丁烯二酸二钠为原料，镍粉为催化剂，对金属催化剂上的固相加氢反应进行了研究。在该研究过程中，发现即使在液相中的产物分析过程中，底物也被氢化成琥珀酸二钠。因此，强烈需要开发一种产品分析程序，以估计在固相中形成的琥珀酸二钠的量。发现镍催化剂的抑制剂处理满足要求。典型的实验程序如下：在固相反应之后，将催化剂抑制剂的甲醇溶液（例如，例如，在一个实施例中，碘化钠和半胱氨酸甲酯盐酸盐）加入到反应混合物（Ni+底物+产物）中。对镍催化剂进行阻聚剂处理后，用H_2O萃取底物和产物，然后进行酯化反应，最后进行GLC分析。通过应用这一程序，可以清楚地看出，在30 ℃和1 × 10^5Pa氢气压力下，虽然反应体系中存在大量过量的氢气，但固相中形成的琥珀酸酯的量最大仅为0.04mmol/g Ni。这一发现表明，在上述反应条件下，少量的基底将被镍表面上的离解氢氢化，并且反应体系中的氢气不能被消耗用于固相反应。在更高温度、更高压力条件下的固相加氢研究正在进行中。

Study on the solid-phase hydrogenation over a metal catalyst was carried out, using disodium fumarate and maleate as substrates and fine nickel powder as a catalyst. In the course of this study, it was found that the substrates were hydrogenated to disodium succinate even in the process of product analysis in the liquid phase. Thus, the development of a product analysis procedure to estimate the amount of disodium succinate formed in the solid phase was strongly required. An inhibitor treatment of the nickel catalyst was found to satisfy the requirement. A typical experimental procedure is as follows ; after the solid phase reaction, a methanol solution of catalyst inhibitor(e. g., sodium iodide and cysteine methyl ester hydrochloride) is added to the reaction mixture(Ni+substrate+product(s)). The inhibitor treatment of the nickel catalyst is followed by the extraction of the substrate and product(s) with H_2O *the esterification of the substrate and product(s)*GLC analysis. By the application of this procedure it was made clear that the amount of succinate formed in the solid phase was only 0.04mmol/g Ni in the maximum at 30ﾟC and at 1x10^5Pa hydrogen pressure, although a large excess of hydrogen gas was present in the reaction system. This finding suggests that a small amount of the substrate would be hydrogenated with dissociated hydrogen on the nickel surface and the hydrogen gas in the reaction system could not be consumed for the solid phase reaction under the above reaction conditions. The studies on the solid phase hydrogenation under severer conditions (higher temperature, higher pressure) are now in progress.