Development of Low-temperature-liquid-phase-methanol-synthesis

由于低温燃烧，甲醇被期望用作不产生任何NOx的燃料。甲醇还可作为燃料电池能源的氢源和化工中间体。有望开发出经济的生产方法。低温甲醇合成是一项有待开发的新技术。提出了两步反应机理：CH_3OH +CO→HCOOCH_3（醇盐催化剂）（1）HCOOCH_3+2H_2→2CH_3OH（镍催化剂）（2）反应机理及催化剂的作用。众所周知，第一步是用Na醇盐催化剂的容易反应。我们使用Co、Fe、Cu、Pd和Ni进一步研究了第二步。其中Ni的效果最好，A和Fe的效果较好.在Co金属上发生另一反应，甲烷化。醇钠的存在导致第二步反应生成甲醇，否则发生分解（HCOOCH_3→CH_3OH+CO）。迄今为止，只有活化H_2的金属表面被认为是第二反应的催化剂。然而，在这项研究中，钠醇盐和金属（特别是镍）的组合被发现是一个重要因素的选择性形成甲醇。Ni颗粒尺寸发生变化。变更甲醇钠的量。变更甲醇钠的量。最后，甲醇钠的比例和表面原子量的镍被发现是重要的。甲醇可导致形成一些中间体（可能是HCHO），其可进一步氢化得到甲醇。镍和甲醇钠的最佳组合可获得99%的产率和98%的甲醇选择性。这些结果表明，该催化剂体系是一种有前途的第二代甲醇合成催化剂体系。

Methanol is expected to be used as a fuel which does not yield any NOx because of low temperature combustion. Methanol also be used as a hydrogen source of fuel cell energy and as an intermediate of chemical industry. Economical production method is expected to be developed. Low temperature methanol synthesis as a new technology to be developed. The two step mechanism has been proposed.CH_3OH+CO→HCOOCH_3 (alkoxide catalyst) (1)HCOOCH_3+2H_2→2CH_3OH (nickel catalyst) (2)The mechanism and the role of catalyst was studied. The first step is well known to be an easy reaction with Na alkoxide catalyst. We studied further the second step using Co, Fe, Cu, Pd, and Ni. Ni was the best and a and Fe showed a good function. On Co metal the other reaction, methanation occurred. Co existence of Na alkoxide leaded the second reaction to methanol synthesis, otherwise the decomposition occurred (HCOOCH_3→CH_3OH+CO). So far only metal surface which activate H_2 is acknowledged as a role of catalyst for the second reaction. However, in this study, the combination of Na alkoxide and metal (especially Ni) was found to be an important factor for the selective formation of methanol. Ni particle size was changed. Amount of Na methoxide was changed. Amount of Na methoxide was changed. Finally the ratio of Na methoxide and the surface atom amount of Ni was found to be important. Methoxide may lead the formation of some intermediate (possibly HCHO), which further may be hydrogenated to give methanol. The best combination of Ni and Na methoxide gave 99% yield and 98% methanol selectivity. These results suggested that this catalyst system be a promising system of second generation methanol synthesis.