As global energy sources transition towards renewable energy, the demand for sustainable fuels has never been greater. The sheer scale of this transition will require numerous solutions to accommodate for the diverse and complex situations worldwide. This dissertation will discuss 3 studies: the utilization of CO2 waste gas to produce fuels sustainably, characterizing biofuels for efficient use in automobiles, and developing a solid, emissonless fuel intended for spaceflight but also applicable on Earth. The hydrogenation of CO2 into value-added molecules could reduce greenhouse gas emissions if waste stream CO2 were captured for conversion. We found that atomic vacancies induced in defect-laden hexagonal boron nitride (dh-BN) can activate the CO2 molecule for hydrogenation. Subsequent hydrogenation to formic acid (HCOOH) and methanol (CH3OH) occur through vacancy-facilitated co-adsorption of hydrogen and CO2. Boron and nitrogen are abundant elements, making h-BN an attractive catalyst in the synthesis of value-added molecules, facilitating efforts to reduce GHG emissions. Biofuels could be vital in a sustainable fuel future. However, their implementation into existing engines requires an understanding of their interactions with engine components at temperature. The formation of carbon deposits on hot metal components can reduce engine performance. Using a novel test rig and gasoline and diesel analog compounds, the degree of fuel degradation to form carbon can be measured on various metal surfaces. Thus, we can screen for low soot-forming biofuels as promising candidates surface on the market. Historically, innovations in space exploration have led to immensely beneficial applications on Earth. Currently, various limitations of power sources hinder the capacity for regular and frequent space exploration. The ability to harvest heat for electrical power would reduce the cost of long-distance and long-duration missions. Employing a regulated, self-propagating, exothermic chemical reaction, we have devised a slow-burning reactant system capable of generating heat at a harvestable rate
