Table 3. Selection criteria and recommended targets for LOHC Systems.

Category	Selection parameter	Recommended target	Justifications	References
Physical properties	Melting point	<30 °C	Avoid solidification; no solvent addition	66
	Boiling point	>300 °C	Low vapour pressure enables easier H2 purification	46
	Viscosity	Low dynamic viscosity	Facilitates pumping and infrastructure compatibility	46
Storage capacity	Gravimetric capacity	> 6 wt% (≥5 wt% at tank system level)	Competitive hydrogen density	11, 66 and 67
	Volumetric capacity	>56 kgH2 m−3	Comparable to compressed hydrogen storage	66
Energy density	Volumetric energy density	>1.6 MWh m−3 (LHV basis)	Competitive with liquid fuels	11 and 67
Thermodynamics	Hydrogen binding enthalpy	30–50 kJ molH2−1 (42–54 kJ mol−1 acceptable range)	Enables dehydrogenation < 200 °C at ∼1 bar	66
Energy efficiency	Dehydrogenation energy demand	≤ 10 kWh per kg H2 (thermal)	Techno-economic competitiveness	11 and 67
Reaction kinetics	Dehydrogenation rate	>3 gH2 g−1 catalyst/min	Industrially viable hydrogen release rate	11 and 67
Selectivity	Conversion/selectivity	>90% conversion; > 99.8% selectivity	Minimise side reactions and degradation	11 and 67
Durability	Performance degradation	<0.01% per cycle	Long service life; reduced replacement cost	11 and 67
Compatibility	Impurity tolerance	Up to 20% impurities in H2 feed	Compatible with mixed gas hydrogenation streams	11 and 67
Economics	Production cost	Low-cost, scalable synthesis	Essential for large-scale deployment	46
Infrastructure	Logistics compatibility	Compatible with existing fuel infrastructure	Reduces CAPEX	66
Safety & environment	Toxicity	Non-toxic, non-hazardous	Must comply with transport and environmental regulations	46