Discuss the role of catalysts, reactor design, and process control in achieving desired reaction outcomes. Explain the significance of reaction mechanisms and selectivity in product formation, considering factors like kinetics, thermodynamics, and reaction conditions. Additionally, analyze the impact of process variables, such as temperature, pressure, and concentration, on reaction rates and product yields. Illustrate practical examples from industries like petrochemicals, pharmaceuticals, and renewable energy, highlighting advancements in sustainable production methods.