Pressure and temperature dependence of methane pyrolysis and hydrogen production in a micro flow reactor

Mohammad R. Razavi; Ömer L. Gülder

Home/Archive/arXiv

arXiv · 2609.31741

Pressure and temperature dependence of methane pyrolysis and hydrogen production in a micro flow reactor

Mohammad R. Razavi·Ömer L. Gülder

View original source ↗Read source document ↗Export metadata ↓

Abstract

Methane pyrolysis experiments were performed in a micro flow reactor to investigate the chemical mechanism sensitivities at elevated pressures and temperatures. The micro flow reactor used in this study provides independent control over reaction parameters. Experiments were performed at temperatures from 1400 to 1800 K and pressures from 1 to 10 bar at a fixed residence time of 60 ms. The yields of hydrogen, unreacted methane, and solid carbon were quantified for comparison to predictive models. The mass of heterogeneous depositions was also quantified. The presence of C2 and PAH species were measured by GC-MS. The results were compared to 1D simulations using a discrete sectional model for capturing the kinetics of particulate formation and surface deposition. The simulations replicated the pressure trend well at high temperatures (1800 K), but the sensitivity to temperature was in disagreement. Simulations generally found lower carbon and hydrogen yields and a stronger sensitivity to temperature than the experiment. An abundance of PAH intermediates was measured at lower temperatures and higher pressures. The simulated surface deposition rates were lower than the measured values but showed similar profiles. The results demonstrate the utility of micro flow reactors in recreating pyrolysis environments for hydrogen production from methane. The predictive capabilities of simulations could be improved by advancing the fuel decomposition and PAH formation and consumption kinetics at low temperatures and by detailed treatment of surface site density.

Explore related subjects

physics.chem-ph

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Mohammad R. Razavi, Ömer L. Gülder. 2026-09-23. Pressure and temperature dependence of methane pyrolysis and hydrogen production in a micro flow reactor. https://arxiv.org/abs/2609.31741

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Resolving Peak Shifting Effects in Real-Time Time-Dependent Orbital Propagation Methods Through Nonorthogonal Expansions

Self-consistent field real-time electronic structure methods are a powerful approach for modeling ultrafast processes but suffer from systematic errors in predicted transition energies, commonly known as peak shifting, that obscure direct comparison with experiment. Although this effect has been explored in single reference methods, a general understanding that extends to multiconfigurational methods remains unresolved. Here, we develop a real-time nonorthogonal multiconfigurational self-consistent field (RT-TD NOMCSCF) formalism in which independently propagated orbital sets generate a compact, nonorthogonal wavefunction. The approach establishes a unified framework for nonlinear real-time electronic structure theories, which we use to reveal the common origin of peak shifting across single and multireference limits. Using this framework, we demonstrate that peak shifting does not arise exclusively from the effect of state averaging over the internal space basis, but also from the accessible external configurational space. By systematically expanding the internal space with independently propagated orbital sets, RT-TD NOMCSCF suppresses this aver- aging, recovers correct transition energies, and distinguishes intrinsic peak shifting from numerical peak drifting caused by propagation errors. Thus, these developments establish nonlinear real-time electronic structure methods that enables more accurate simulations of ultrafast processes.

physics.chem-ph↗

arXiv2026

Zero photoemission from icosahedral superatoms

Photoemission is expected to occur when the photon energy exceeds the binding energy of an electron, with the photoemission yield generally remaining non-zero above this threshold. Yet, it can be suppressed at specific photon energies, a phenomenon known as the Cooper minimum. Although complete suppression represents an extreme limit of this phenomenon, such zero photoemission has previously been reported only for atoms with an outermost s-type orbital and has never been observed in non-atomic systems. Here, we demonstrate the deliberate realization of zero photoemission from Ag12W-, an artificial icosahedral superatom, by observing a vanishing photoemission cross section 0.85 eV above the detachment threshold and reproducing this behavior in theoretical simulations. These simulations predict that zero photoemission can be common in nearly spherical nanoclusters, a prediction we experimentally confirm using Ag12Mo-, an isoelectronic counterpart of Ag12W-. Because superatoms offer systematic control over both size and elemental composition using the periodic table, our findings establish a route toward active control of photoemission in finite-size quantum systems and stimulate further investigations of underexplored physical phenomena such as nondipole effects.

physics.chem-ph↗

arXiv2026

Near Chemical Accuracy From Size-Consistent Padé Resummed Møller-Plesset Perturbation Theory

Padé resummation of the correlation energy from Møller-Plesset (MP) perturbation theory is not size-consistent and is therefore seldom used. We present an orbital-based Padé resummation of the MP2 and MP3 self-energy operators, whose trace yields a size-consistent correlation energy. We find that damping the third-order same-spin contribution leads to substantially increased accuracy, with the resulting same-spin damped orbital Padé resummed (SSD-OPMP3) approach attaining near-chemical accuracy (mean absolute error $\sim$ 1 kcal/mol) for total atomization energies of non-multireference molecules in the W4-17 dataset against the gold standard CCSD(T) method. Excellent performance surpassing CCSD is also obtained for other molecular datasets such as those containing barrier heights, noncovalent interactions, dipole moments, static polarizabilities, and transition-metal chemistry. SSD-OPMP3 is thus a highly accurate electronic structure method with the same noniterative $O(N^6)$ cost as MP3, filling a gap in the cost/accuracy hierarchy of wavefunction methods.

physics.chem-ph↗