A bottom-up approach to prepare cobalt-based bimetallic supported catalysts for hydrolysis of ammonia borane

摘要

Catalysis is an important research topic in the field of hydrogen generation by hydrolysis of boron-based hydrides. A typical example is hydrolysis of ammonia borane (AB, NH_3BH_3), 1 mol of which is able to liberate up to 3 mol H_2 at temperatures lower than 80 "C. However, the presence of a catalyst, generally metal-based, is necessary. The present work was thus conducted in this framework. Herein, we propose a bottom-up approach to prepare cobalt-based bimetallic supported catalysts. The general idea was: first, to screen cobalt-based bimetallic nanoparticles and select the best combination, which was found to be CoCu with a weight ratio 70:30 - its reactivity was discussed in terms of electronic and geometric effects; second, to prepare Ni foam-supported CoCu through a 2-stage process - CoCu/Ni showed a hydrogen generation rate of ca. 25 mL min which almost 5 times better than that observed for the monometallic counterparts Co/Ni and Cu/Ni; third, to propose a new concept of CoCu supported catalysts using a plastic film (light, easy to handle and to prepare) — it showed to be stable and, despite a low hydrogen generation rate (because most of the nanoparticles were embedded in the film), totally converted AB. Our main results are reported and discussed herein.