Efficient hydrogen production from NaBH4 hydrolysis catalyzed by a magnetic cobalt/carbon composite derived from a zeolitic imidazolate framework
Efficient hydrogen production from NaBH4 hydrolysis catalyzed by a magnetic cobalt/carbon composite derived from a zeolitic imidazolate framework
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DOI：
10.1016/j.cej.2016.03.115
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发表时间：
2016-07
影响因子：
15.1
通讯作者：
K. Lin;Hsuan-Ang Chang
中科院分区：
文献类型：
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作者：
K. Lin;Hsuan-Ang Chang
虽然钴被认为是NaBH 4水解制氢最有效的催化剂之一，但纳米钴催化剂容易聚集，降低了其催化活性。虽然纳米级钴催化剂可以固定在基底上以防止聚集，但固定化涉及后修饰，导致制备时间长和过程复杂。在这项研究中，我们开发了一种易于制备的碳载钴材料，该材料来源于钴基沸石咪唑骨架（ZIF-67）。通过一步碳化，ZIF-67很容易转化为多孔磁性钴/碳复合材料（MCCC）。MCCC的磁性、孔隙率和钴含量使其成为一种很有前途的NaBH 4制氢催化剂。这是ZIF-67的这种衍生物用于催化NaBH 4水解以产生H2的第一个实例。考察了催化剂用量、温度和NaOH浓度对反应的影响。MCCC对NaBH 4的水解具有很高的催化活性，即使在没有NaOH存在的情况下也能很好地催化NaBH 4的水解。在碱性条件下，MCCC显示出上级催化能力和显著低的活化能（即，25.8 kJ mol−1）。MCCC在5次循环中水解NaBH 4时，不需要冲洗，也表现出稳定和有效的可循环性。这些性质使MCCC成为一种有效和实用的NaBH 4制氢多相催化剂。
While cobalt is recognized as one of the most efficient catalysts for H2production from NaBH4hydrolysis, nanoscale cobalt catalysts tend to aggregate, decreasing their catalytic activities. Although nanoscale cobalt catalysts can be immobilized on substrates to prevent aggregation, immobilization involves post modifications, leading to long preparation time and complex procedures. In this study, we develop an easy-to-prepare carbon-supported cobalt material derived from a cobalt-based Zeolitic Imidazolate Framework (ZIF-67). Via one-step carbonization, ZIF-67 is readily transformed to a porous magnetic cobalt/carbon composite (MCCC). The magnetism, porosity and cobalt content of MCCC make it a promising catalyst for H2production from NaBH4. This is the first instance in which such a derivative of ZIF-67 is used to catalyze NaBH4hydrolysis for H2production. Effects of catalyst loading, temperature and NaOH concentration were thoroughly examined. MCCC exhibited an efficient catalytic activity to hydrolyze NaBH4even in the absence of NaOH. Under alkaline conditions, MCCC shows a superior catalytic capability with significantly low activation energy (i.e., 25.8 kJ mol−1). MCCC also exhibited stable and efficient recyclability to hydrolyze NaBH4over 5 cycles without rinsing. These properties make MCCC an effective and practical heterogeneous catalyst for H2production from NaBH4.