The coupling effect of polymeric vanadyl species greatly promotes the NH ₃ -SCR de-NO _x process over vanadia-based catalysts.

Natural gas vehicles (NGVs), as alternatives to gasoline and diesel vehicles, have been rapidly and widely promoted in the past 20 years. The three-way catalyst (TWC) technology is one of the dominant technologies for gaseous emission control of NGVs. However, it is still a great challenge to purify the exhaust gas of NGVs to meet increasingly strict emission limits, particularly for CH₄ and NO_x. This review is focused on the recent research advances in TWCs for NGVs, including the technical fundamentals, classic components (active phases, supports, and promoters), novel preparations of catalysts, resistance to thermal and chemical aging, current challenges and future perspectives. Particular attention is given to Pd-based catalysts as typical commercial TWCs, and potential alternatives which have competitive three-way catalytic performance are also highlighted.

It is a great challenge for vehicles to satisfy the increasingly stringent emission regulations for pollutants and greenhouse gases. Throughout the history of the development of vehicle emission control technology, catalysts have always been in the core position of vehicle aftertreatment. Aiming to address the significant demand for synergistic control of pollutants and greenhouse gases from vehicles, this review provides a panoramic view of emission control technologies and key aftertreatment catalysts for vehicles using fossil fuels (gasoline, diesel, and natural gas) and carbon-neutral fuels (hydrogen, ammonia, and green alcohols). Special attention will be given to the research advancements in catalysts, including three-way catalysts (TWCs), NO_x selective catalytic reduction (SCR) catalysts, NO_x storage-reduction (NSR) catalysts, diesel oxidation catalysts (DOCs), soot oxidation catalysts, ammonia slip catalysts (ASCs), methane oxidation catalysts (MOCs), N₂O abatement catalysts (DeN₂O), passive NO_x adsorbers (PNAs), and cold start catalysts (CSCs). The main challenges for industrial applications of these catalysts, such as insufficient low-temperature activity, product selectivity, hydrothermal stability, and poisoning resistance, will be examined. In addition, the future development of synergistic control of vehicle pollutants and greenhouse gases will be discussed from a catalysis perspective.