Catalytic synthesis of neutral hydrogen peroxide at a CoN2Cx cathode of a polymer electrolyte membrane fuel cell (PEMFC).
Catalytic synthesis of neutral hydrogen peroxide at a CoN2Cx cathode of a polymer electrolyte membrane fuel cell (PEMFC).
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DOI：
10.1002/cssc.200900246
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发表时间：
2010-01
期刊：
影响因子：
8.4
通讯作者：
I. Yamanaka;S. Tazawa;T. Murayama;T. Iwasaki;S. Takenaka
中科院分区：
文献类型：
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作者：
I. Yamanaka;S. Tazawa;T. Murayama;T. Iwasaki;S. Takenaka
H2 O2的工业生产目前使用多步蒽醌法进行。[1]生产成本和运输复杂性限制了H2 O2在许多应用中的广泛使用，例如碳氢化合物的选择性氧化和生活环境的消毒。[2]已经研究了直接生产方法，包括使用Pd和Au-Pd催化剂在酸或甲醇溶液中从H2 O2的H2和O2催化合成H2 O2 [3-9]。然而，催化方法涉及H2和O2的挥发性和爆炸性气体混合物。我们报道了一种安全直接生产H2 O2的燃料电池方法。[10-15]在该方法中，由阳极、阴极和酸性或碱性水溶液组成的隔膜分离H2和O2。该方法的缺点是产物（H2 O2溶液）含有酸或碱。[10-16]我们最近改进了燃料电池反应器，并成功地生产了不含任何盐的中性H2 O2溶液。[17新的反应器使用固体聚合物电解质（Nafion-H）和新的阴极催化剂（热处理的Co-TPP/VGCF）（TPP：5，10，15，20-四（苯基）-21H，23 H-卟啉; VGCF：气相生长碳纤维）。通过在He中在573-1273 K下热处理负载在VGCF载体上的Co-TPP的催化剂前体来制备催化剂。基于程序升温脱附（TPD）-质谱和FTIR研究，Co-TPP的热解被认为非常适合于此目的。[19在VGCF上Co-TPP的热解有望形成一种新的Co化合物，并起到活性中心的作用。因此，我们研究了钴卟啉以外的钴配合物的新前体催化H_2O_2的生成，并对活性中心的结构和反应机理进行了研究。我们已经报道了用于形成中性H2 O2溶液的燃料电池反应器的结构。[18]该反应器类似于传统的聚合物电解质膜燃料电池（PEMFC）。将阴极/Nafion-H/阳极的单元固定到双室电池。阴极由催化剂油墨制备，所述催化剂油墨由电催化剂粉末（4 mg）、Nafion-H溶液（20 μL）和2-丙醇（200 μL）制成，超声混合并涂覆在基底电极（2cm 2，VGCF 48 mg，PTFE 3 mg）的一侧上;然后将阴极的该涂覆面附着到Nafion-H膜。阳极（2cm 2）由50重量% Pt/炭黑（Pt/XC-72，25 mg）、VGCF（25 mg）和PTFE（5 mg）粉末制备。将电极
The industrial manufacture of H2O2 is currently performed using the multistep anthraquinone process.[1] Production costs and transport complications limit the wider use of H2O2 for many applications, such as selective oxidation of hydrocarbons and disinfecting living environments.[2] Direct production methods including catalytic synthesis of H2O2 from H2 and O2 of H2O2 using Pd and Au–Pd catalysts in acid or methanol solutions,[3–9] have been investigated. However, the catalytic methods involve volatile and explosive gas mixtures of H2 and O2.We have reported a fuel cell method for the safe and direct production of H2O2.[10–15] In this method, a diaphragm composed of an anode, a cathode, and an acid or alkaline aqueous solution separates H2 and O2. A drawback of this method is that the product (H2O2 solution) contains acid or base.[10–16] We recently improved the fuel cell reactor and succeeded in producing a neutral H2O2 solution without any salts.[17, 18] The new reactor uses a solid-polymer electrolyte (Nafion-H) and a new cathode catalyst (heat-treated Co-TPP/VGCF)(TPP: 5, 10, 15, 20-tetrakis (phenyl)-21H, 23H-porphyrin; VGCF: vapor-growing carbon fibre). The catalyst was prepared by heat treatment of a catalyst precursor of Co-TPP loaded on a VGCF support in He at 573–1273 K. Pyrolysis of Co-TPP was considered highly suitable for this purpose on the basis of temperature-programmed desorption (TPD)-mass and FTIR studies.[19, 20] A new Co compound is expected to be formed by pyrolysis of Co-TPP on VGCF and function as an active site. Therefore, we investigated new precursors of the Co complex, other than Co-porphyrin, to catalyze the formation of H2O2, and studied the structure of the active site and the reaction mechanisms. We have already reported the structure of a fuel cell reactor for the formation of neutral H2O2 solution.[18] The reactor resembles a conventional polymer electrolyte membrane fuel cell (PEMFC). A unit of the cathode/Nafion-H/anode is fixed to a two-compartment cell. The cathode was prepared from catalyst ink made from electrocatalyst powder (4 mg), Nafion-H solutions (20 μL) and 2-propanol (200 μL), mixed ultrasonically and painted on one side of a base electrode (2cm2, VGCF 48 mg, PTFE 3 mg); this painted face of the cathode was then attached to the Nafion-H membrane. The anode (2 cm2) was prepared from 50wt% Pt/carbon black (Pt/XC-72, 25mg), VGCF (25 mg) and PTFE (5 mg) powders. The electrodes were