Transitioning to lower carbon energy and environment sustainability requires a reduction in greenhouse gases such as carbon dioxide (CO₂) and methane (CH₄) that contribute to global warming. One of the most actively studied rare earth metal catalysts is cerium oxide (CeO₂) which produces remarkable improvements in catalysts in dry reforming methane. This paper reviews the management of CO₂ emissions and the recent advent and trends in bimetallic catalyst development utilizing CeO₂ in dry reforming methane (DRM) and steam reforming methane (SRM) from 2015 to 2021 as a way to reduce greenhouse gas emissions. This paper focus on the identification of key trends in catalyst preparation using CeO₂ and the effectiveness of the catalysts formulated.

On the basis of its properties, ethanol has been identified as the most used biofuel because of its remarkable contribution in reducing emissions of carbon dioxide which are the source of greenhouse gas and prompt climate change or global warming worldwide. The use of ethanol as a new source of biofuel reduces the dependence on conventional gasoline, thus showing a decreasing pattern of production every year. This article contains an updated overview of recent developments in the new technologies and operations in ethanol production, such as the hydration of ethylene, biomass residue, lignocellulosic materials, fermentation, electrochemical reduction, dimethyl ether, reverse water gas shift, and catalytic hydrogenation reaction. An improvement in the catalytic hydrogenation of CO₂ into ethanol needs extensive research to address the properties that need modification, such as physical, catalytic, and chemical upgrading. Overall, this assessment provides basic suggestions for improving ethanol synthesis as a source of renewable energy in the future.