INFEWS N/P/H2O: Fundamentals of N2/O2 plasma and heterogeneous catalysis

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

1606062 PI: Graves Title: INFEWS N/P/H2O: Fundamentals of N2/O2 plasma and heterogeneous catalysis This project aims to advance air plasma technology in order to substantially reduce human perturbation to the global nitrogen cycle. The focus will be on establishing the scientific foundation necessary to efficiently couple non-equilibrium nitrogen/oxygen plasmas with heterogeneous catalysts in order to efficiently form nitric oxide (NO). If efficient air plasmas can create nitric oxide (NO), this can be readily transformed to nitogen oxide (NO2) and then to nitric acid (HNO3) by water absorption. Nitric acid could be used to trap otherwise fugitive ammonia (NH3), created when bacteria degrade organic waste. The ammonia is trapped at low pH as ammonium nitrate (NH4NO3), thus greatly increasing the nitrogen value of the organic fertilizer and avoiding the damaging environmental effects of the ammonia emission. The technology would be especially promising because the plasma can be powered by electricity that could be generated in a distributed, renewable fashion at the location of the waste generation, such as the farm. Rather than compete with conventional Haber-Bosch NH3 manufacturing technology, this technology seeks to reduce the need for synthetic fertilizers made in centralized plants far from their use. Non-equilibrium plasmas can act as a homogeneous catalyst by lowering the activation energy of nitrogen dissociation. This process can be substantially improved by the addition of heterogeneous catalysts, but the underlying mechanisms are poorly understood. The proposed project will employ radical beam - surface studies under high vacuum and modulated beam mass spectrometry to study radical-surface catalytic interactions for a range of metal and metal oxide materials and surface temperatures. The data from these studies will be used to develop parameterized site balance models that can provide insights into near-atmospheric pressure studies of non-equilibrium nitrogen/oxygen plasmas in the presence of catalytic surfaces. The successful implementation of plasmas for this application could help motivate studies of other plasma electro-catalytic technologies. In addition to training graduate students, the PI plans to recruit undergraduate students from programs that engage women and minorities. An outreach program to middle school students involving plasma demonstration devices is also proposed.