Addition of excess nitrogen to water sources, mainly in the form of nitrates from fertilizers, leads to harmful algal blooms of cyanobacteria. These algal blooms contaminate drinking water, causing health problems for humans in addition to harming the species living in the aquatic ecosystem. Nitrogen pollution in water is increasingly concerning as nitrogen-based fertilizers are being used to help feed the growing population. Nitrate, which exists in the highest oxidation state of nitrogen (+5), is difficult to reduce at low concentrations and does not form a practical insoluble metal precipitate. Ideally, the nitrate would be reduced to environmentally benign N2, with an oxidation state of 0. The copper-based pre-catalyst, K2[Cu(pinF)2], first synthesized by Willis and co-workers and later characterized in greater detail by the Doerrer group, is capable of electrocatalytically reducing nitrate and nitrite in water at a pH of 12. Time-dependent, solution phase 15N NMR data of the nitrate reduction process show that nitrite and ammonium constitute most of the aqueous products. However, 24% of the products are unaccounted for by 15-N NMR studies and are assumed to be gaseous.  This poster will report the results of mass-spectroscopic analysis of the gases formed during bulk electrolysis. We will use a membrane inlet mass spectrometer (MIMS) to measure natural abundance and 15N-labled N2, N2O, NO, and NO2 concentrations, and their changes in time.  Such data will enable tuning of the catalyst, ideally to shift the reduction products to exclusively N2. <br/>

Tracking reduced nitrogen from electrocatalytic reduction of nitrate by a Cu-based precatalyst

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.