The titled reaction is assumed to proceed via an insertion mechanism. Statistical branching ratios for various product channels are predicted with RRKM rate constants that are obtained based on ab initio calculations. A modified collision-complex model is utilized in the estimation of absolute reaction cross-sections for primary channels. The product energy partitions for H and H-2 formation pathways are obtained. Subsequently, the RRKM rate constants for secondary reactions are calculated with correction for the translational and rotational energies of primary products. The results give insight to reaction mechanism and provide probable explanations to disputes among previous experimental findings. (C) 2003 Elsevier B.V. All rights reserved.