Sustainable Conversion of Carbon, Nitrogen and Water into HCN and CO at Atmospheric Pressure and Near Ambient Temperature

At near ambient conditions (1 atm, 25-40 oC) carbon (sustainable charcoal, graphite powder, milled carbon fibres) and nitrogen are converted into HCN and CO by a Non-Thermal Plasma (NTP) discharge using a previously unrecognised C2 diradical N2 activation route. The O-atoms within the CO result ultimately from carbon-absorbed water. A stepwise ensemble comprising: cyanogen formation (from excited state C2 and N2), its subsequent cleavage to HCN, the Water-Gas-Shift-Reaction (WGSR) and Boudouard reaction (CO from CO2/C) provide the observed products. No conversion of carbon is observed in the absence of NTP, but in its presence, NTP-synergistic aluminium xerogel catalysts [prepared from hydrolysis of Al(O-sec-Bu)3 in the presence of methanol soluble transition metal salts (Fe, Mg, Mo, Na, Cu, Ag)] control the reaction selectivity. For the optimal Fe(II)-xerogel concentrations of 5900-6019 ppm (ca. 0.6% HCN v/v) and 39032-63200 ppm (ca. 5% CO v/v) are reached at dissipated powers of 0.14 W mL-1.min.