Hydrogen (H2) is used mainly in the chemical industry for the production of ammonia and methanol. In the future, hydrogen is expected to become a significant fuel that able to decrease the dependence on fossil fuels and will largely contribute to the quality of atmospheric air. The most substantial contemporary hydrogen production technology is the steam reforming of hydrocarbons from natural gas, such as methane, which is currently the primary source of catalytic hydrogen production. Various transition metal like Nickel (Ni), Cobalt (Co), Ferrous (Fe), and Platinum ( Pt) shows higher tendency to decompose methane into carbon-free hydrogen. Methane can be directly thermally or thermo-catalytically decomposed to carbon and hydrogen without emission of CO2 or CO, according to the following reaction: a) The methane decomposition process can be done via the Langmuir-Hinshelwood type mechanism. Provide a reasonable Langmuir-Hinshelwood kinetic mechanism that may well represent the overall reaction occur which involved the adsorption of CH4 molecule on the active site. Adsorption of methane on the surface is a rate-controlling step, and reversible. The surface reaction is a dual-site mechanism where adsorbed methyl radicals and adsorbed hydrogen atoms are formed on the catalyst surface, due to the removal of the hydrogen atom gradually from molecularly adsorbed methane. Based on the proposed mechanism, derive the rate expression for the overall reaction. (10 marks) b) Ni-based catalysts were widely investigated in the decomposition of methane for hydrogen production due to their high activity. It has been reported that hydrogen could already be detected at 200C in the presence of a freshly prepared Ni catalyst. However, the threshold Ni nanoparticle size affects the rate of methane dissociation which exceeds the rate of the oxidation bringing to the carbon formation on the metal as filaments. It was also found that during the reaction process using Ni-based catalyst shaped in the packed-bed reactor, the performance of the reactor reduced. With proper citation(s), explain the causes which bring these problems and provide the solutions. Provide the list of relevant reference(s) in your answers. (15 marks)