整体式功能纳米碳催化剂在工业气中硫化氢选择氧化脱除的应用研究

The nanocarbon catalysts present superior activity, selectivity and stability in industrial H2S oxidation reaction (Super-Claus reaction) for selective production of elemental sulfur, which could be considered as an alternative desulfurization catalyst compare to traditional metal catalysts. However, the nanocarbon materials (such as carbon nanotube and porous nanocarbons) are used in powder form which inevitably induces significant pressure drop along the catalyst bed as reported elsewhere and also renders it difficult for transportation and handling. Moreover, the optimization of active sites and the mechanism of H2S selective oxidation on nanocarbon materials are still not clear. In this proposal, we will develop the macroscopic shaped nanocarbon materials with controllable surface properties to obtain the efficient desulfurization catalysts. The reaction kinetics and mechanism in H2S selective oxidation will be also devoted to the optimization studies on the reaction conditions and the catalyst structure. The optimized catalysts for the probe reactions under industrial relevant reaction conditions, i.e. long-term evaluation in the presence of impurities such as CO2, CO and NH3, and advanced characterization regarding the structure-activity relationship will also be studied in detail. This research is valuable not only for rational design of macroscopic shaped catalysts with excellent performances, but also be promising to find way strategies for selective oxidation of H2S over environmental metal-free catalysts.

纳米碳催化剂在工业气中H2S高温选择氧化生成单质硫的反应（Super-Claus 反应）中逐渐体现出可替代过渡金属催化剂的巨大潜力。然而纳米碳材料以粉体为主，在工业使用过程中将面临运输和回收难、反应床层压力降大等问题，限制了其在脱硫领域的应用。同时其在高温脱硫反应中的活性位和催化机理也仍不明确。因此，本课题将制备整体式纳米碳材料并通过调控其表面物化性质，以获得高效脱硫催化剂。以纳米碳管和多孔纳米碳为重点研究对象，通过应用各种材料合成和改性手段，研制表面官能团改性和杂原子掺杂的整体式纳米碳基催化剂，在此基础上主要考察整体式纳米碳催化剂的表面化学特性以及掺杂对H2S选择氧化的活性、选择性和稳定性的影响。在模拟工业反应条件下，通过探讨纳米碳材料催化H2S选择氧化的反应机理，阐明纳米碳结构以及表面化学性质与其催化行为的构效关系；同时希望能为纳米碳非金属催化在环境领域的应用研究开辟一条新路径。

传统工业催化中使用的金属或金属氧化物催化剂具有较差的稳定性，不容易再生以及对环境存在潜在的污染等问题引起了人们对绿色可持续性催化剂体系的研究与探索。纳米碳材料因比表面积大、具有丰富的化学性质、环境友好和容易再生等优点，在工业气中H2S高温选择氧化生成单质硫的反应（Super-Claus反应）中逐渐体现出可替代过渡金属催化剂的巨大潜力。该项目主要开展整体式的功能性纳米碳材料在硫化氢选择氧化反应上的性能研究。开发了高效的纳米碳材料的表面处理手段，将臭氧-溶剂蒸汽（水、乙醇、双氧水等）作为氧化剂能够获得高效、特定官能团比例的功能纳米碳催化材料。并通过对碳基催化材料的结构调控、孔结构的优化以及非金属杂原子（N掺杂，P掺杂以及N/P共掺杂等）修饰来对纳米碳材料表面物理化学结构进行调控，发展了高活性、高选择性、高稳定性的硫化氢选择氧化反应的整体式纳米碳基催化剂。与此同时，该整体式纳米碳催化剂机械强度高，在工业应用中容易运输和回收，并且能降低床层压力降大等问题，增加了在工业反应中的应用潜力。项目在模拟工况反应条件下，制备的纳米碳基材料具有很好的抗CO2和H2O等杂质气体的能力，进一步推动了整体式碳催化剂在工业反应中应用的进程。