Achieving volatile potassium promoted ammonia synthesis via mechanochemistry
Jonghoon Kim, Tianyi Dai, Mihyun Yang, Jeong‐Min Seo, Jae Seong Lee, Do Hyung Kweon, Xingyou Lang, Kyuwook Ihm, Tae Joo Shin, Gao‐Feng Han, Qing Jiang, Jong‐Beom Baek
Abstract
Abstract Potassium oxide (K 2 O) is used as a promotor in industrial ammonia synthesis, although metallic potassium (K) is better in theory. The reason K 2 O is used is because metallic K, which volatilizes around 400 °C, separates from the catalyst in the harsh ammonia synthesis conditions of the Haber-Bosch process. To maximize the efficiency of ammonia synthesis, using metallic K with low temperature reaction below 400 °C is prerequisite. Here, we synthesize ammonia using metallic K and Fe as a catalyst via mechanochemical process near ambient conditions (45 °C, 1 bar). The final ammonia concentration reaches as high as 94.5 vol%, which was extraordinarily higher than that of the Haber-Bosch process (25.0 vol%, 450 °C, 200 bar) and our previous work (82.5 vol%, 45 °C, 1 bar).