摘要
Cobalt is commonly admitted as being a promising catalyst in accelerating NaBH4 hydrolysis,being as reactive as noble metals and much more cost-effective.This is the topic of the present paper.Herein,we survey(i) the NaBH4-devoted literature while especially focusing on the Co catalysts and(ii) our work on the same topic.Finally,we report(iii) reactivity results of newly developed Co-based catalysts.From both surveys,it mainly stands out that Co has been investigated as catalysts in various forms:namely,as chlorides,reduced nanoparticles(metal Co,Co boride,Co-B alloy),supported over supports and shaped.In doing so the reactivity can be easily varied achieving H2 generation rates from few to 】1000 L(H2)/min·g(metal).Nevertheless,our work can be distinguished from the NaBH4 literature.Indeed,we are working on strategies that focus on making alternative Co-based catalysts.One of these strategies is illustrated here as we report new reactivity data of Co-based bimetallic supported catalysts.For example,we show that 20 wt% Co90Y10/γAl2O3-20 wt% Co95Hf5/γAl2O3 】 20 wt% Co99Zr1/γAl2O3 】 20 wt% Co/γAl2O3,the best catalysts showing HGRs of about 245 mL(H2)/min or 123 L(H2) /min·g(metals).
Cobalt is commonly admitted as being a promising catalyst in accelerating NaBH4 hydrolysis,being as reactive as noble metals and much more cost-effective.This is the topic of the present paper.Herein,we survey(i) the NaBH4-devoted literature while especially focusing on the Co catalysts and(ii) our work on the same topic.Finally,we report(iii) reactivity results of newly developed Co-based catalysts.From both surveys,it mainly stands out that Co has been investigated as catalysts in various forms:namely,as chlorides,reduced nanoparticles(metal Co,Co boride,Co-B alloy),supported over supports and shaped.In doing so the reactivity can be easily varied achieving H2 generation rates from few to >1000 L(H2)/min·g(metal).Nevertheless,our work can be distinguished from the NaBH4 literature.Indeed,we are working on strategies that focus on making alternative Co-based catalysts.One of these strategies is illustrated here as we report new reactivity data of Co-based bimetallic supported catalysts.For example,we show that 20 wt% Co90Y10/γAl2O3-20 wt% Co95Hf5/γAl2O3 > 20 wt% Co99Zr1/γAl2O3 > 20 wt% Co/γAl2O3,the best catalysts showing HGRs of about 245 mL(H2)/min or 123 L(H2) /min·g(metals).
