LASER-INDUCED FLUORESCENCE AND MASS-SPECTROMETRIC STUDIES OF THE CU -FORMATION OF HCUCL+HCL REACTION OVER A WIDE TEMPERATURE RANGE

The kinetics and products of the Cu + HCl reaction have been studied u sing high-temperature fast-flow reactors (HTFFR). The rate coefficient measurements were made using laser-induced fluorescence (LIF) of Cu a toms and yielded k(680-1500 K) = 1.2 x 10(-10) exp(-7719 K/T) cm(3) mo lecule(-1) s(-1). Product analysis was achieved by coupling a speciall y designed HTFFR to a chopped molecular beam quadrupole mass spectrome ter. Those observations, which covered the approximately 1150-1500 K t emperature range, showed formation of CuCl and the previously unknown species HCuCl. Confirmation of the latter assignment was made using DC l. Increasing pressure and decreasing temperature favor the HCuCl form ation. These findings and this molecular structure are supported by ab initio calculations. These also indicate passage through a CuClH --> HCuCl transition state as the rate-controlling step for formation of b oth products, in agreement with the observed pressure independence of the overall, Cu disappearance, rate coefficients.