Advanced Catalytic Systems for Environmental Applications

催化作用在日常生活的方方面面无处不在。的确，如果没有催化作用，我们所知道的地球上的生命就不可能存在，而使合成氨成为可能的催化剂的发明是历史上一个伟大的转折点。近年来，我们受到许多环境问题的困扰，包括温室气体排放导致的全球变暖。为了减少交通运输部门的温室气体排放，很多人都把重点放在使用天然气作为燃料上，天然气目前储量丰富、价格低廉，而且还具有产生很少颗粒的额外优势。与其他碳氢化合物燃料相比，它产生的每能量单位产生的温室气体最少。然而，天然气发动机和其他所有发动机一样，并没有燃烧100%的燃料，因此废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产生的大部分温室气体效益就会丧失。自2016年以来，甲烷一直是一种受控排放，唯一的方法是通过使用催化转化器来破坏它。不幸的是，甲烷是最难催化燃烧的碳氢化合物，通常需要很高的温度。目前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。所需要的催化剂也有显著不同的属性，这取决于是否有过量的氧气（稀薄燃烧）或它存在于化学计量量。天然气汽车尾气处理后，迫切需要一种有效的催化剂。我们最近展示了用于稀燃发动机运行的改进催化剂，这可能会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，并且持续足够长的时间，以满足化学计量天然气燃料发动机的要求。首要目标是开发一种优于目前可用的最佳催化剂的催化剂，而不考虑贵金属的负载，次要目标是开发含有较少贵金属的催化剂，以降低总体成本。

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.