A Methanol-Tolerant Pt/CoSe2 Nanobelt Cathode Catalyst for Direct Methanol Fuel Cells
A Methanol-Tolerant Pt/CoSe2 Nanobelt Cathode Catalyst for Direct Methanol Fuel Cells
复制标题
用于直接甲醇燃料电池的耐甲醇 Pt/CoSe2 纳米带阴极催化剂
DOI：
10.1002/anie.201007036
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发表时间：
2011-01-01
影响因子：
16.6
通讯作者：
Yu, Shu-Hong
中科院分区：
文献类型：
--
作者：
Gao, Min-Rui;Gao, Qiang;Yu, Shu-Hong
直接甲醇燃料电池（DMFC）已经受到了相当大的和持续的关注，因为甲醇是一种丰富的，廉价的液体燃料，比氢更容易储存和运输。[1]尽管在这一领域取得了很大的进步，仍然必须考虑影响效率和功率密度的两个主要问题，即燃料电池阳极反应的缓慢动力学和所谓的甲醇渗透。[2]甲醇小分子可以很容易地通过DMFC的聚合物膜从阳极侧跨越到阴极侧，然后直接与阴极催化剂和O2反应，从而降低阴极电位，从而降低燃料效率。解决该问题的一种方法是开发用于氧还原反应（ORR）的耐甲醇阴极催化剂。最近对耐甲醇催化剂的研究表明，过渡金属大环化合物[3]、Ru基硫族化物[4]和一些铂基合金[5]都显示出耐甲醇性，同时保留了ORR的催化活性。然而，不利因素仍然存在。例如，在燃料电池条件下，不含Pt的电催化剂通常表现出低得多的活性和较差的长期稳定性;[6] Pt基合金阴极电催化剂仅适用于低金属负载，因此不太适合DMFC。[7]因此，开发具有相当稳定性和高ORR活性的新型耐甲醇电催化剂是重要的。目前，钴硫族化合物作为新型ORR电催化剂引起了人们极大的兴趣。[8]硫化钴如Co 3S 4和Co 9 S8在酸性电解质中对四电子ORR相当活跃。[9]此外，硒化钴[10]和碲化钴[11]显示出电催化的ORR活性。特别地，由Alonso-Vante等人制造的CoSe 2/C纳米颗粒表现出良好的甲醇耐受性。[12]然而，这些材料的ORR活性仍然较低，离直接甲醇燃料电池的应用还很远。最近，我们描述了一种合成策略，允许在二元溶液中大规模制造层状介观结构的CoSe 2/二乙烯三胺（DETA）纳米带。[13]层状纳米带与以前的钴硫族化物相比具有几个优点：均匀分布，丰富的表面氨基，允许负载高度分散的金属纳米颗粒，以及在强酸性条件下的优异稳定性。基于这些优点，我们期望可以在此材料的基础上设计出高性能的耐甲醇电催化剂。在这里，我们报告了一种新的耐甲醇的Pt/CoSe 2纳米带的DMFC应用的电催化剂，可以通过原位负载Pt纳米粒子CoSe 2/DETA纳米带通过多元醇还原方法合成。Pt/CoSe 2电催化剂在酸性介质中表现出较高的ORR催化活性。更重要的是，这种纳米杂化结构对甲醇具有很强的耐受性，即使在浓度高达5m.Mesostructured CoSe 2/DETA纳米带首次合成高产率通过一个简单的溶剂热策略先前报道. [13]然后，Pt纳米粒子原位合成CoSe 2/DETA纳米带的表面上，通过一个简单的多元醇还原方法。[14]多层CoSe 2/DETA纳米带具有高度的耐酸性，尽管硒化物通常容易受到酸的攻击。[15]H2SO 4处理方法遵循Kanatzalan等人最近关于用强酸处理介观结构cC 20 PyPtSnSe材料的报道。[16]H2SO 4处理过的样品保留了原始CoSe 2/DETA纳米带的结晶性质和生长方向[13]（参见支持...
Direct methanol fuel cells (DMFCs) have received considerable and persistent attention, because methanol is an abundant, inexpensive liquid fuel that is easier to store and transport than hydrogen.[1] Despite the great advances made in this field, two main issues affecting efficiency and power density must still be considered, that is, sluggish kinetics of the fuel-cell anode reaction and so-called methanol crossover.[2] The small methanol molecule can easily cross over from the anode to the cathode side through the polymer membranes of DMFCs, and then reacts directly with the cathode catalyst and O2 to decrease the cathode potential and thus reduce fuel efficiency. One approach to addressing this problem is the development of methanol-tolerant cathode catalysts for the oxygen reduction reaction (ORR). Recent research on methanol-tolerant catalysts has shown that transition metal macrocycles,[3] Ru-based chalcogenides,[4] and some platinumbased alloys [5] all show methanol tolerance while retaining catalytic activity for the ORR. Nevertheless, disadvantages still exist. For instance, Pt-free electrocatalysts often show much lower activity and inferior long-term stability under fuel-cell conditions;[6] Pt-based alloy cathode electrocatalysts are available only with low metal loading and thus are not quite suitable for DMFCs.[7] Therefore, development of novel methanol-tolerant electrocatalysts with considerable stability and high ORR activity is important. Currently, cobalt chalcogenides are attracting enormous interest as new ORR electrocatalysts.[8] Cobalt sulfides such as Co3S4 and Co9S8 are rather active for four-electron ORR in acidic electrolytes.[9] In addition, cobalt selenides [10] and tellurides [11] show electrocatalytic ORR activity in nanocrystal form. In particular, the CoSe2/C nanoparticles fabricated by Alonso-Vante et al. exhibit good methanol tolerance.[12] However, the ORR activity of these materials is still low, and they are far from DMFC application. Recently, we described a synthetic strategy that allows large-scale fabrication of ultrathin lamellar mesostructured CoSe2/diethylenetriamine (DETA) nanobelts in a binary solution.[13] The lamellar nanobelts have several advantages over previous cobalt chalcogenides: homogeneously distributed, copious surface amino groups that allow loading of highly dispersed metal nanoparticles, and exceptional stability under strongly acidic conditions. With these merits, we expect that methanoltolerant electrocatalysts with high performance can be designed on the basis of this material. Here we report that a new methanol-tolerant Pt/CoSe2 nanobelt electrocatalyst for DMFC applications can be synthesized by in situ loading of Pt nanoparticles on CoSe2/DETA nanobelts through a polyol reduction approach. The Pt/CoSe2 electrocatalysts display relatively high ORR catalytic activity in acidic medium. More importantly, the nanohybrid structures are highly resistant to methanol, even at concentrations of up to 5m.Mesostructured CoSe2/DETA nanobelts were first synthesized in high yield by a simple solvothermal strategy reported previously.[13] Then, Pt NPs were synthesized in situ on the surface of CoSe2/DETA nanobelts through a facile polyol reduction approach.[14] The multilayered CoSe2/DETA nanobelts are highly acid resistant, although selenides are generally vulnerable to attack by acids.[15] The H2SO4 treatment process is followed the recent report by Kanatzidis et al. on treatment of mesostructured cC 20PyPtSnSe materials with strong acids.[16] The H2SO4-treated sample retains the singlecrystalline nature and growth direction of the original CoSe2/DETA nanobelts [13](see Supporting …