We here report that by using electronegative gas of iodine and CO2 under negative corona discharge, tetraiodomethane could be synthesized at 70?°C and 1?atm without any catalyst, despite thermodynamically infeasible at ambience without electron discharge. The conversion of carbon dioxide reached 88.71?% at a gas flow rate of 0.06?L/min and a discharge frequency of 9.608?kHz. The anion-involved CO2 reduction process could be implemented efficiently under mild conditions, avoiding high temperature and high pressure. 相似文献
A sampling campaign including summer, autumn and winter of 2014 and spring of 2015 was accomplished to obtain the characteristic of chemical components in PM2.5 at three sites of Kunming, a plateau city in South-west China. Nine kinds of water-soluble inorganic ions (WSI), organic and element carbon (OC and EC) in PM2.5 were analyzed by ion chromatography and thermal optical reflectance method, respectively. Results showed that the average concentrations of total WSI, OC and EC were 22.85±10.95 µg·m-3, 17.83±9.57 µg·m-3 and 5.11±4.29 µg·m-3, respectively. They totally accounted for 53.0% of PM2.5. Secondary organic and inorganic aerosols (SOA and SIA) were also assessed by the minimum ratio of OC/EC, nitrogen and sulfur oxidation ratios. The annual average concentrations of SOA and SIA totally accounted for 28.3% of the PM2.5 concentration. The low proportion suggested the primary emission was the main source of PM2.5 in Kunming. However, secondary pollution in the plateau city should also not be ignorable, due to the appropriate temperature and strong solar radiation, which can promote the atmospheric photochemical reactions.