Ben Yaala Marwa, Saeedi Arsalan, Scherrer Dan-Felix, Moser Lucas, Steiner Roland, Zutter Marco, Oberkofler Martin, De Temmerman Gregory, Marot Laurent, Meyer Ernst
Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland.
Phys Chem Chem Phys. 2019 Jul 31;21(30):16623-16633. doi: 10.1039/c9cp01139k.
Plasma catalysis has drawn attention in the past few decades as a possible alternative to the Haber-Bosch process for ammonia production. In particular, radio frequency plasma assisted catalysis has the advantage of its adaptability to the industrial scale. However, in the past years, very few experimental studies have focused on the synthesis of ammonia from nitrogen/hydrogen radio frequency plasma. As a consequence, to date, there has been little agreement about the complex mechanisms underlying the radio frequency plasma-catalyst interactions. Gaining such an understanding is therefore essential for exploiting the potential of radio frequency plasma catalysis for ammonia production. In this study, we present results of ammonia formation from a nitrogen/hydrogen radio frequency plasma both without and with a tungsten catalyst for different initial nitrogen ratios. High yields of ammonia up to 32% at 25/75% of nitrogen/hydrogen were obtained using a combination of radio frequency low pressure plasma and a W surface as a catalyst. Furthermore, based on chemical analysis of the catalytic surface composition, a formation pathway of ammonia via the Eley-Rideal mechanism between adsorbed nitrogen and hydrogen from the gas phase is presented.
在过去几十年中，等离子体催化作为一种可能替代哈伯-博施法生产氨的方法受到了关注。特别是射频等离子体辅助催化具有适应工业规模的优势。然而，在过去几年里，很少有实验研究聚焦于由氮/氢射频等离子体合成氨。因此，迄今为止，关于射频等离子体与催化剂相互作用的复杂机制几乎没有达成共识。所以，了解这些对于挖掘射频等离子体催化生产氨的潜力至关重要。在本研究中，我们展示了在不同初始氮比下，有无钨催化剂时氮/氢射频等离子体生成氨的结果。使用射频低压等离子体和钨表面作为催化剂的组合，在氮/氢比例为25/75%时可获得高达32%的高氨产量。此外，基于对催化表面成分的化学分析，提出了一种通过吸附氮与气相氢之间的埃利-里德机理生成氨的途径。
