Most of the world’s hydrogen is still made from natural gas – and most of that process releases CO₂. Methane pyrolysis takes a different route: it splits methane into hydrogen and solid carbon, so the carbon leaves the reactor as a solid rather than as a gas. Researchers at Stanford University have now tackled one of the two main obstacles that have kept the process confined to the lab – and discovered a potentially valuable by-product along the way.
The scaling problem: getting the heat in
Methane pyrolysis has been studied for years, but two challenges have prevented it from reaching industrial scale: removing the solid carbon from the reactor, and supplying enough heat to drive the reaction at temperatures of around 1,000 °C. Today’s reactors are heated from the outside. That works in the lab, but in a large reactor the heat struggles to reach the core. The new study, published in Science, focuses on the second challenge.
Heating from within by burning a little hydrogen
Instead of firing the reactor with natural gas, the team placed a burner inside it that selectively combusts a share of the hydrogen being produced. The combustion product is mostly water, so no direct CO₂ is emitted, and the heat is generated exactly where it is needed. According to the researchers, this autothermal approach yields roughly a tenfold gain in efficiency: with the same energy input, one internally heated reactor produces as much as ten conventionally heated ones.
The work was led by co-first authors Henry Moise and Sebastian Moll, a visiting student from Germany, in the group of Matteo Cargnello, associate professor of chemical engineering at Stanford. Eric McFarland’s team at the University of California, Santa Barbara contributed data on larger reactors; funders included the Kavli Foundation, the Carbon Hub at Rice University, Stanford’s Natural Gas Initiative and the CO₂ Research Center at Aarhus University.
The surprise: high-quality graphite
The biggest surprise for the team was the carbon itself. The solid by-product turned out to be highly graphitised – graphite of a quality used in electrodes, batteries and other technologies. A saleable carbon product could significantly improve the economics of pyrolysis hydrogen. The researchers caution, however, that the graphite is not yet pure enough for demanding applications such as battery materials, and that scale-up and verification for mainstream hydrogen production are still to come.
The Power-to-X perspective: it all depends on the methane
From SPIN’s perspective, the decisive question is not the reactor but the feedstock. Pyrolysis of fossil natural gas avoids CO₂ at the plant, yet it still depends on extracting fossil carbon – and on a gas supply chain whose methane leaks weigh heavily on the climate balance. That is cleaner fossil hydrogen, not defossilisation.
The picture changes with renewable methane. If the feedstock is biomethane, the carbon locked into the graphite was originally taken from the atmosphere by plants. As long as the graphite is used in durable products rather than burned, the process can deliver hydrogen and a lasting carbon sink at the same time. Synthetic methane made from renewable energy with recycled CO₂ could play a similar role where the gas grid is used to store and transport energy and hydrogen is needed at the end of the line – although converting renewable hydrogen into methane and back again is only worthwhile where this logistics advantage outweighs the conversion losses.
Switzerland already has practical experience with the technology: in November 2025, the VZDI and its partners, including SPIN member Empa, inaugurated the country’s first industrial methane pyrolysis plant at V-ZUG in Zug, which uses a microwave plasma. Different heating concepts, the same goal: making methane pyrolysis work at industrial scale. Combined with biomethane, it could become a useful building block of a defossilised hydrogen supply.
Source: Stanford University, via TechXplore, “Improved method for producing sustainable hydrogen offers a surprising side benefit” (3 September 2026); Henry Moise et al., “Autothermal methane pyrolysis: Scalable heat integration for hydrogen and graphite production”, Science (2026), DOI 10.1126/science.aed4911.
H2 Forum 2026 – 14 October, Konstanz
How can the hydrogen market ramp-up succeed in the trinational Lake Constance and Upper Rhine region? The H2 Forum 2026 of the Trinational Hydrogen Initiative 3H2 brings together politics, industry and infrastructure operators at the Bodenseeforum in Konstanz on 14 October 2026 – with panels, workshops and practical examples from across the region.
🤖 AI transparency: This text and its visual were created using AI, reviewed and approved by a human.