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Methane is the primary industrial H2 source, with the vast majority produced by steam reforming of methane—a highly CO2- and water-intensive process. Alternatives to steam reforming, such as microwave-driven plasma-mediated methane decomposition, offer benefits of no water consumption and zero CO2 process emissions while also producing solid carbon formed by pyrolytic reactions and aided by a plasma reactive environment. The economic viability of pyrolytic methane decomposition as a hydrogen source will depend upon the commercial applications of the solid carbon product—which, in turn, will depend upon its physical and chemical characteristics. This study focuses on material characterization of the solid carbon (secondary) product. Characterization by high-resolution transmission electron microscopy reveals forms ranging from graphitic to amorphous. Thermogravimetric analyses reveal three forms by their differing oxidative reactivity, while X-ray diffraction analyses support the different crystalline forms as suggested by Thermogravimetric analysis. Plasma perturbation of the radical pool, elevating radical temperatures and boosting concentrations, is proposed as altering the reaction paths towards solid carbon formation, resulting in the different sp2 forms.

A test procedure was designed and employed for exposure and degradation testing of well cements in a simulated downhole environment of offshore deep drilling. A Class H cement sample was crushed to coarse grains and was exposed to 5 % mass NaCl(aq) solution in contact with CO2 at 100 °C and 10 MPa for 200 hours. Key ionic species were identified from the aqueous phase from the testing to develop the cement synthetic pore solution (CSPS) recipe. The CSPS was then used for corrosion characterization of high chromium well casing steel at the same conditions of the cement exposure for 60 hours. The corrosion potential in the measurements ranged between -0.4 and -0.5 V vs. SHE. The average corrosion rate of the steel samples was on the order of 0.1 mm/year, representing a worst-case scenario for degradation of the cement material, but significant for critical steel components like a well casing.

This work investigates the dielectric quality and interface properties of TiN/Hf 1-x Zr x O 2 /Al 2 O 3 /Ge gate stacks with six different Zr content (0%, 25%, 33%, 50%, 75%, and 100%). The dielectrics were subjected to Slot-Plane Antenna Plasma Oxidation (SPAO) after the ALD deposition process prior to metal deposition. The equivalent oxide thickness (EOT), flat-band voltage (V FB ), interface state density (D it ), C-V hysteresis, and leakage current (I-V) behavior were analyzed. It was observed that EOT decreases with Zr addition in HfO 2 with up to 75% of Zr incorporation. While the devices with up to 75% of Zr demonstrated lower C-V hysteresis, flat-band voltage shift and mid-gap D it tend to increase with decrease in EOT. With 100% Zr incorporation EOT increased significantly while reducing the mid-gap D it . This behavior is mostly dependent on GeO x -like interfacial layer formation and defects at the interface. Weibull plots shows that charge to breakdown (Q BD ) increased with increase in the Zr percentage. However, the breakdown acceleration factor decreased with Zr percentage up to 75% and increased for 100% Zr content.