A MXene-enabled platform for methane decomposition, catalyst stability, and carbon upcycling

Catalytic decomposition of methane (CDM) is a promising route for COx free hydrogen production with simultaneous generation of valuable solid carbon. In this work, two-dimensional titanium based MXene was employed for the first time as a template for a Ni catalyst to evaluate its influence on methane conversion, hydrogen yield, carbon formation, and spent catalyst valorization. At 550 °C in a fixed bed reactor, the catalyst showed stable performance for 10 h without deactivation or pressure drop issues, achieving a high carbon yield of 2296%, indicating strong resistance to carbon-induced deactivation. The maximum methane conversion of 37% was obtained at a space velocity of 5000 mLh−1gcat−1. Fishbone type carbon nanofibers with high structural quality were formed. Notably, the spent catalyst exhibited excellent supercapacitor performance, delivering an areal capacitance of 130 μF cm−2 with good rate capability and excellent stability over 5000 cycles.