Technological Transitions and Thermodynamic Optimisation in Steam Methane Reforming for Sustainable Hydrogen Production: A Critical Review of Catalyst Deactivation, Process Intensification and Carbon Capture Integration

Abstract

Steam methane reforming remains the dominant industrial route to hydrogen, and its future depends on whether the process can be reconciled with deep decarbonisation objectives. This review critically examines three research streams that have developed largely in isolation from one another: the thermodynamic and kinetic constraints that govern conventional reforming, the deactivation behaviour of nickel-based reforming catalysts, and the competing intensification and carbon capture architectures proposed to reduce emissions. Literature published between 1984 and May 2026 was identified through structured searching of openly accessible scholarly metadata indexes and appraised for methodological adequacy, evidential strength and internal consistency. The synthesis indicates that the thermodynamic penalties of conventional reforming are well characterised, and that the principal deactivation mechanisms of carbon formation, nickel sintering and sulphur chemisorption are mechanistically understood at the level of model systems. Translation of that understanding into predicted industrial catalyst lifetimes is considerably weaker, because most formulation studies report short isothermal tests conducted under conditions that differ substantially from reformer tube environments. Intensified configurations, including sorption-enhanced reforming, membrane and membrane-assisted reactors, chemical looping and gas switching schemes, and electrified reforming, each relax a specific equilibrium or heat transfer constraint, yet the supporting evidence is dominated by simulation and short-duration laboratory demonstration. Sorbent capacity decay, membrane durability under realistic feed impurities and oxygen carrier attrition remain the principal barriers, and each is inconsistently reported. Studies of carbon capture integration converge on the finding that capture from the shifted syngas is less costly than capture from reformer flue gas but cannot by itself deliver very high overall capture rates. Life cycle assessments diverge sharply, and the divergence originates in assumptions about upstream methane emissions and system boundaries rather than in the underlying process models. Research priorities identified include standardised long-duration testing protocols, transparent reporting of degradation trajectories, and life cycle studies grounded in measurement-based methane emission factors.