Nitric acid oxidation of cyclohexane accounts for ~95% of the worldwide adipic acid production and is also responsible for ~5 to 8% of the annual worldwide anthropogenic emission of the ozone-depleting greenhouse gas nitrous oxide (N
2
O). Here we report a N
2
O-free process for adipic acid synthesis. Treatment of neat cyclohexane, cyclohexanol, or cyclohexanone with ozone at room temperature and 1 atmosphere of pressure affords adipic acid as a solid precipitate. Addition of acidic water or exposure to ultraviolet (UV) light irradiation (or a combination of both) dramatically enhances the oxidative conversion of cyclohexane to adipic acid.
环己烷的硝酸氧化占全球己二酸产量的约95%,也占全球年人为排放的臭氧层破坏温室气体一氧化二氮(N2O)的5%至8%。我们报道了一种无N2O的己二酸合成工艺。在室温和1大气压下,对纯环己烷、环己醇或环己酮进行臭氧处理,生成己二酸作为固体沉淀。加入酸性水或暴露于紫外(UV)光照射(或两者结合)显著增强了环己烷氧化转化为己二酸。