Advanced Catalytic Systems for Environmental Applications

催化作用在日常生活的各个方面无处不在。事实上，没有催化剂，我们所知道的地球上的生命就不可能存在，而合成氨的催化剂的发展是历史上的一个伟大转折点。近年来，我们受到许多环境问题的困扰，包括温室气体排放造成的全球变暖。在减少运输部门温室气体排放的努力中，人们一直非常关注使用天然气作为燃料，天然气目前储量丰富，价格便宜，并且具有产生少量颗粒的额外优势。与其他碳氢化合物燃料相比，它产生的每能源单位温室气体最少。然而，与所有其它发动机一样，天然气发动机并不燃烧100%的燃料，因此在排气流中可能存在大量的甲烷。如果这些气体被排放到大气中，那么使用甲烷作为燃料所带来的温室气体效益将大部分丧失。自2016年以来，甲烷一直是一种受控的排放物，唯一的方法是通过使用催化转化器来销毁它。不幸的是，甲烷是最难催化燃烧的碳氢化合物，通常需要高温。现有的最好的催化剂是基于铂和钯的，但这些催化剂在水的存在下会受到严重的失活影响。所需的催化剂还具有显著不同的属性，这取决于是否存在过量的氧（贫燃）或其是否以化学计量的量存在。迫切需要一种有效的催化剂，用于处理天然气燃料车辆的废气。我们最近已经证明了用于稀燃发动机操作的改进的催化剂，这可能导致改进的商业催化剂。然而，这些配方将不适合化学计量操作，这似乎是目前汽车工业的主要趋势。该项目的主要目标是开发一种稳定的甲烷氧化催化剂，该催化剂将有效地发挥作用，并持续足够长的时间，以满足化学计量天然气燃料发动机的要求。主要目的是开发一种上级目前可用的最佳催化剂的催化剂，而不管贵金属负载量如何，次要目的是开发具有减少量的贵金属的催化剂以降低总成本。

Catalysis is ubiquitous in all aspects of daily life. Indeed, without catalysis, life on earth as we know it would not be possible, and the development of the catalyst that allowed the synthesis of ammonia is one of the great turning points in history. In recent times, we are plagued with many environmental problems, including global warming caused by greenhouse gas emissions. In a drive to reduce GHG from the transportation sector, there has been a lot of focus on using natural gas as a fuel, which is currently abundant and cheap, and has the added advantage of producing few particulates. It produces the least amount of GHG per energy unit produced, compared to other hydrocarbon fuels. however, the natural gas engine, like all others, does not burn 100% of the fuel, and therefore significant amounts of methane can be present in the exhaust stream. If these are emitted to the atmosphere, much of the GHG benefit of using methane as a fuel would be lost. Since 2016 methane has been a controlled emission, and the only way to destroy it is through the use of a catalytic converter. Unfortunately, methane is the most difficult hydrocarbon to combust catalytically, and normally requires a high temperature. The best catalysts available are based around platinum and palladium, but these suffer from severe deactivation effects in the presence of water. The catalyst required also has significantly different attributes depending on whether or not there is an excess of oxygen (lean burn) or it is present in stoichiometric amounts. There is a desperate need for an effective catalyst for the exhaust gas after treatment from natural gas fueled vehicles. We have recently demonstrated improved catalysts for the lean burn engine operation, which may lead to improved commercial catalysts. However, these formulations will not be appropriate for stoichiometric operation, which seems to be the major trend for the automobile industry at present. The main objective of this project is the development of a stable methane oxidation catalyst that will function effectively, and for a sufficient length of time, to meet the requirements of a stoichiometric natural gas fueled engine. The primary objective is to develop a catalyst that is superior to the best catalysts currently available, regardless of precious metals loading, and the secondary objective is to develop catalysts with reduced amounts of precious metals to reduce the overall cost.