Method for catalytically induced hydrolysis and recycling of metal borohydride solutions

A process for preparing a metal-borohydride decomposition catalyst, the process comprising depositing an alloy of formula M3xR onto a surface of a cathode, the deposition being carried out in a solution under induced constant cathode potential, M being a reduced metal, R being an element selected from P, B and N, and x being between 2 and 3 wherein said process comprises the steps of:

• providing a solution comprising a source of M3 metal cations and a reductant comprising the element R;
• immersing the cathode, an anode and a reference electrode into the solution;
• applying a current between the anode and the cathode, while inducing a constant electric potential (E) on the cathode, as measured versus the reference electrode, thereby permitting reduction of M3 and oxidation of the reductant to obtain the deposition of M3xR alloy onto the cathode, the constant electric potential being lower than the reduction potential of the M3 metal cation;
• and
• annealing the cathode at elevated temperatures under an inert gas atmosphere.