Advanced Catalytic Systems for Environmental Applications

催化普遍存在于日常生活的方方面面。事实上，没有催化，我们所知的地球上的生命就不可能存在，而能够合成氨的催化剂的发展是历史上的伟大转折点之一。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。在减少运输部门温室气体排放的努力中，人们非常关注使用天然气作为燃料，天然气目前储量丰富，价格低廉，而且还有一个额外的优势，即产生的颗粒物很少。与其他碳氢燃料相比，它每单位产生的温室气体最少。然而，天然气发动机和所有其他发动机一样，不会100%燃烧燃料，因此废气流中可能会存在大量甲烷。如果这些气体排放到大气中，使用甲烷作为燃料所带来的温室气体好处就会丧失很大一部分。自2016年以来，甲烷一直是一种受控排放，销毁它的唯一方法是使用催化转化器。不幸的是，甲烷是最难催化燃烧的碳氢化合物，通常需要较高的温度。现有的最好的催化剂是以铂和钯为基础的，但这些催化剂在水存在时会受到严重的失活影响。所需的催化剂也具有显著不同的属性，这取决于是否存在过剩的氧气(稀薄燃烧)或以化学计量的量存在。目前迫切需要一种有效的催化剂来处理天然气汽车排放的废气。我们最近展示了用于稀燃发动机运行的改进的催化剂，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，这似乎是目前汽车行业的主要趋势。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，并可持续足够长的时间，以满足化学计量比天然气发动机的要求。主要目标是开发一种优于目前最好的催化剂的催化剂，无论贵金属含量如何，次要目标是开发贵金属含量较少的催化剂，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.