In Situ Catalytic Functionalization of Cooling Channels: Novel Strategy for Efficient Cracking of Hydrocarbon Fuels

Abstract

Abstract

Catalytic cracking plays a pivotal role in enhancing the pyrolysis efficiency of endothermic hydrocarbon fuels for advanced propulsion systems. Conventional approaches, typically based on coated or quasi-homogeneous catalysts, suffer from complex fabrication procedures and inadequate long-term stability, limiting their practical application. Herein, this work develops an in situ chemical functionalization strategy that converts the inner surface of metallic cooling channels into active catalytic interfaces. With GH3128 alloy, a widely used Ni-based alloy for aerospace cooling channels, this work performs in situ high-temperature oxidation to form the M x O y substrate, followed by Pt loading to construct the composite catalyst. Characterizations via SEM, EDS, Raman, XRD, and XPS confirm that this strategy yields uniform Pt distribution and a catalytic layer with good adhesion to the alloy substrate. The cracking performance evaluated in the distributed flow calorimeter at 3.5 MPa, 1.0 g/s, and 675 °C shows significant improvement: the heat sink and the decalin conversion ratio increase from 2.38 MJ/kg and 39.0% to 2.64 MJ/kg and 53.5%, respectively. The density functional theory calculations reveal that the in situ Pt-M x O y catalyst can substantially reduce the adsorption and dehydrogenation energy barriers of decalin during the cracking process. The findings highlight in situ catalytic functionalization of cooling channels as a promising and viable strategy toward advanced, high-performance thermal management systems for hypersonic vehicles.