Herein we demonstrate the synthesis of ammonia via atmospheric dielectric barrier discharge (DBD) plasma over nickel nanoparticles supported on silica. We evaluated the performance of nickel nanoparticles with average sizes of 5.6 nm and 13.5 nm. The smallest nanoparticle size sample resulted in an ammonia synthesis rate at least 2 times higher than that of the larger nanoparticle size sample and nickel bulk at equimolar composition. This allowed us to observe experimentally, for the first time, the size effect in the area of plasma catalysis. Moreover, the presented results allowed us to investigate a hydrogen sink metal such as nickel under atmospheric plasma conditions and determine the gas composition that resulted beneficial for this surface chemistry.

本文中，我们证明了通过大气介电势垒放电（DBD）等离子体在负载在二氧化硅上的镍纳米粒子上合成氨。我们评估了平均粒径为5.6 nm和13.5 nm的镍纳米粒子的性能。最小的纳米颗粒尺寸样品产生的氨合成速率至少比较大的纳米颗粒尺寸样品高2倍，并且在等摩尔组成下镍的堆积量更高。这使我们第一次能够通过实验观察到等离子体催化领域的尺寸效应。此外，提出的结果使我们能够在大气等离子体条件下研究氢沉金属（例如镍），并确定对这种表面化学有利的气体成分。