Nickel, cobalt, and Ni-Co alloy nanopowders prepared by plasma-assisted milling: Catalytic activity in the carbon dioxide reforming of methane

Abstract

The nanopowders of Ni and Co metals and their alloy were prepared by plasma-assisted milling, and the activity of catalysts on their basis was studied in the carbon dioxide reforming of methane (CDRM) at atmospheric pressure. It was found that the catalytic activity of Ni nanopowder rapidly decreased because of the blocking of its surface by coking products. Co powder exhibited lower but stable activity, which gradually decreased as a result of coking only 300 h after the onset of reaction. A Ni-Co alloy (1: 1, by weight) is an active and selective catalyst for CDRM. Its catalytic activity appeared at 400°C; at 870°C, conversion reached 90% and remained unchanged for 500 h. The initial activity was restored by the regeneration of a catalyst based on the Ni-Co alloy with molecular hydrogen for several hours at 400°C.