Early-Stage Evaluation of Additively Manufactured Joule-Heated Carbon Architectures for Electrified Methane Cracking

Electrified chemical reactors are emerging as a promising route for decarbonizing hydrogen production processes. In this work, additively manufactured carbon architectures have been investigated as directly Joule-heated supports for methane pyrolysis. Periodic open cellular structures (POCS) based on the rotated cube unit cell were produced using different additive manufacturing techniques, namely, binder jetting and laser powder bed fusion followed by precursor infiltration pyrolysis (PBF + PIP). Different carbon-based constituent materials (i.e., vitreous carbon and graphite) were evaluated for POCS production, while silicon carbide was used as the reference material for direct Joule heating processes. The architected structures simultaneously act as resistive heating elements and catalytic substrates, enabling distributed internal Joule heating within the reactor volume. The heat transfer performance and the catalytic activity of the POCS for methane cracking were tested in a Joule-heated lab-scale reactor. At 4180 h –1 space velocity and 50 vol % methane concentration (N 2 complement), POCS made of vitreous carbon exhibited the highest methane conversion, reaching values up to 92% at 850 °C. Microstructural characterization of the produced carbon revealed graphitic nanoparticles with properties compatible with high-value carbon applications. These results demonstrate the feasibility of additively manufactured Joule-heated architected reactors for methane pyrolysis and highlight the potential of combining electrothermal reactor concepts with architected porous materials for electrified chemical processes.