Mo promoted Ni-ZrO2 co-precipitated catalysts for green diesel production

The promoting action of Mo-species was studied for Ni-ZrO2 co-precipitated catalysts with high nickel loading used in the transformation of sunflower oil into green diesel. The catalysts were thoroughly characterized and evaluated using a high-pressure semi-batch reactor. The significant promoting action of molybdenum species was clearly demonstrated concerning the Ni-ZrO2 catalysts as Mo addition resulted in almost duplication of green diesel yield (from 35.2 to 68.4 %). This is manifested through the acceleration of the hydrodeoxygenation pathway of the reaction network. The increase of the activation temperature increases further the catalytic efficiency of the promoted catalysts resulting in 70.1 % green diesel yield. The promoting action of molybdenum was partly attributed to the increase of the specific surface area and the metallic nickel surface brought about by molybdenum but, principally, to a synergy between the oxygen vacancies developed on the very well dispersed Mo-species - and the nickel surface sites. (c) 2023 Elsevier Ltd. All rights reserved.