Departament d'Enginyeria Química, Universitat Rovira i Virgili, Avda. Països Catalans, 26, Campus Sescelades, Tarragona 43007, Spain.
Water Sci Technol. 2011;63(9):2017-24. doi: 10.2166/wst.2011.452.
A catalytic system for the generation of H2O2 from formic acid and oxygen at ambient conditions has been developed. Pd-supported catalysts (Pd/C, Pd/TiO2 and Pd/Al2O3) have been tested, showing that for bulk purposes Pd/Al2O3 is more favourable while for in-situ applications Pd/TiO2 seems to be preferable. However, when these catalysts were tested in the in-situ H2O2 generation for the oxidation of phenol by means of the Fenton process (in the presence of ferrous ion), Pd/TiO2 did not demonstrate the expected results, whereas Pd/Al2O3 showed to be an efficient catalyst. Therefore, Pd/Al2O3 is offered as a good catalyst for Fenton's reactions with in-situ generated H2O2. In order to optimize the operating cost of the process, different initial concentrations of formic acid have been tested with Pd/Al2O3, and it has been seen that lowering the initial amount of formic acid favours the efficiency of the process. The effect of the addition of a second metallic (Pt, Au, Fe, Cu) active phase was studied. Concerning H2O2 generation, best results were obtained with a Pd-Au catalyst for bulk production (long time) while for in-situ application Pd-Fe showed interesting results. The Pd-Fe catalyst also performed similarly to the semi-heterogeneous Fenton system involving Pd/Al2O3 and ferrous ion in the degradation of phenol. Therefore, Pd-Fe catalyst offered an interesting prospect for making a full heterogeneous catalyst for Fenton reaction involving in-situ generation of H2O2.
已开发出一种在环境条件下将甲酸和氧气转化为 H2O2 的催化体系。测试了负载钯的催化剂（Pd/C、Pd/TiO2 和 Pd/Al2O3），结果表明，对于大规模应用，Pd/Al2O3 更为有利，而对于原位应用，Pd/TiO2 似乎更可取。然而，当这些催化剂在芬顿工艺（在亚铁离子存在下）中用于苯酚氧化的原位 H2O2 生成中进行测试时，Pd/TiO2 并未表现出预期的结果，而 Pd/Al2O3 则表现出高效的催化剂。因此，Pd/Al2O3 被推荐为用于芬顿反应的原位生成 H2O2 的良好催化剂。为了优化该过程的运行成本，使用 Pd/Al2O3 测试了不同初始甲酸浓度，结果表明降低甲酸的初始量有利于提高过程的效率。研究了添加第二金属（Pt、Au、Fe、Cu）活性相的影响。关于 H2O2 的生成，在批量生产（长时间）时，Pd-Au 催化剂获得了最佳结果，而在原位应用时，Pd-Fe 显示出有趣的结果。Pd-Fe 催化剂在苯酚降解方面也与涉及 Pd/Al2O3 和亚铁离子的半均相芬顿体系表现出相似的性能。因此，Pd-Fe 催化剂为开发涉及原位生成 H2O2 的芬顿反应的全非均相催化剂提供了一个有趣的前景。
