title: Influence of temperature on the heterogeneous reaction of formic acid on α-Al2O3.
abstract: Despite increased awareness of the role played by heterogeneous reactions of formic acid on mineral aerosol, the experimental determination of how these atmospheric reaction rates vary with temperature remain a crucially important part of atmosphere science. Here we report the first measurement of heterogeneous uptake of formic acid on α-Al(2)O(3) as a function of temperature (T = 240-298 K) at ambient pressure using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). From the analysis of the spectral features, crystalline HCOOH was identified at low temperature besides common product (formate ions) on the surface. It was also interesting to find that crystalline HCOOH can continue to react with α-Al(2)O(3). The reaction mechanisms at both room and low temperature were discussed. Furthermore, the reactive uptake coefficients were acquired and found to increase with decreasing temperature. Finally, the atmospheric lifetime of formic acid because of heterogeneous loss on mineral aerosol was estimated at temperatures related to the upper troposphere.
authors.affiliation: Beijing National Laboratory for Molecular Science (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
authors.forename: Ling-Yan
authors.initials: LY
authors.lastname: Wu
authors.forename: Sheng-Rui
authors.initials: SR
authors.lastname: Tong
authors.forename: Si-Qi
authors.initials: SQ
authors.lastname: Hou
authors.forename: Mao-Fa
authors.initials: MF
authors.lastname: Ge
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D005561:Formates / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D005561:Formates; C030544:formic acid; D000537:Aluminum Oxide