Porous cotton stalk activated carbons(CSAC)were prepared by phosphoric acid activation of cotton stalks in a fluidized bed.The CSAC-supported Co-B and Co-Ce-B catalysts were prepared by the impregnation-chemical reduc...Porous cotton stalk activated carbons(CSAC)were prepared by phosphoric acid activation of cotton stalks in a fluidized bed.The CSAC-supported Co-B and Co-Ce-B catalysts were prepared by the impregnation-chemical reduction method.The samples were characterized by the nitrogen adsorption,XRD,FTIR and TEM measurements.The effects of the sodium borohydride(NaBH_(4))and sodium hydroxide(NaOH)concentrations,reaction temperature and recyclability on the rate of NaBH_(4)hydrolysis over the CSAC-supported Co-Ce-B catalysts were systematically investigated.The results showed that the agglomeration of the Co-Ce-B nanoclusters on the CSAC support surface was significantly reduced with the introduction of cerium.The CSAC-supported Co-Ce-B catalyst exhibited superior catalytic activity and the average hydrogen generation rate was 16.42 L min^(−1)g^(−1)Co at 25℃,which is higher than the most reported cobalt-based catalysts.The catalytic hydrolysis of NaBH_(4)was zero order with respect to the NaBH_(4)concentration,and the hydrogen generation rate decreased with the increase in the NaOH concentration.The activation energy of the hydrogen generation reaction on the prepared catalyst was estimated to be 48.22 kJ mol^(−1).A kinetic rate equation was also proposed.展开更多
基金The authors gratefully acknowledge the support from the National Key R&D Program(2018YFB06050401)Key R&D program of the Ningxia Hui Autonomous Region(2018BCE01002),Nature Science Foundation of China(21868025)+1 种基金the Key Research&Development Program of Shandong Province(2018GGX104013)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(Grant No.2019-KF30).
文摘Porous cotton stalk activated carbons(CSAC)were prepared by phosphoric acid activation of cotton stalks in a fluidized bed.The CSAC-supported Co-B and Co-Ce-B catalysts were prepared by the impregnation-chemical reduction method.The samples were characterized by the nitrogen adsorption,XRD,FTIR and TEM measurements.The effects of the sodium borohydride(NaBH_(4))and sodium hydroxide(NaOH)concentrations,reaction temperature and recyclability on the rate of NaBH_(4)hydrolysis over the CSAC-supported Co-Ce-B catalysts were systematically investigated.The results showed that the agglomeration of the Co-Ce-B nanoclusters on the CSAC support surface was significantly reduced with the introduction of cerium.The CSAC-supported Co-Ce-B catalyst exhibited superior catalytic activity and the average hydrogen generation rate was 16.42 L min^(−1)g^(−1)Co at 25℃,which is higher than the most reported cobalt-based catalysts.The catalytic hydrolysis of NaBH_(4)was zero order with respect to the NaBH_(4)concentration,and the hydrogen generation rate decreased with the increase in the NaOH concentration.The activation energy of the hydrogen generation reaction on the prepared catalyst was estimated to be 48.22 kJ mol^(−1).A kinetic rate equation was also proposed.
