The process disclosed herein satisfies the need in the art for an industrially viable oxidative carbonylation catalytic system, and is capable of producing carbamates at a significantly higher rate than those processes reported in journal and patent literature. This reaction process takes place via a reaction mechanism that does not involve drastic conditions. Specifically, the catalytic system of the present invention employs Group VIII metal catalysts and/or copper-based catalysts with halide promoters to produce carbamates through heterogeneous oxidative carbonylation at atmospheric pressure and relatively non-drastic temperatures in a gas-solid carbonylation process.