Transition metal phosphide catalysts for the chemical storage of renewable hydrogen

Transition metal phosphides (TMP) are highly interesting catalytic materials for future hydrogenation and dehydrogenation reactions, as required for chemical hydrogen storage (e.g. Liquid organic hydrogen carriers). The state-of-the-art synthesis of these TMPs includes either harmful by-products (e.g. phosphine), harsh conditions (e.g. high temperatures) or time-consuming purification steps. In this study a novel synthesis path for TMP is examined, starting with the example dinickel phosphide. The novel method uses phosphonium-salts as phosphorous source, allowing to overcome the previously mentioned disadvantages of other methods. A variation of the synthesis parameters, calcination temperature, nickel salt and phosphonium salt was performed and compared to Ni2P that has been synthesized via the standard temperature programmed reduction (TPR) method. In the next step, the transfer of the synthesis method to different transition metals was examined. The new dinickel phosphide catalyst was finally tested for selective hydrogenation of acetophenone.