The article reviews recent advancements in the electrochemical reduction of CO₂ (CO₂RR) under acidic conditions, addressing the "carbonate issue" that arises in neutral or alkaline electrolytes. The "carbonate issue" refers to the formation of (bi)carbonate byproducts, which reduces the overall carbon utilization efficiency and complicates device-level applications. Conducting CO₂RR in acidic electrolytes offers a promising solution, but it presents challenges due to the enhanced hydrogen evolution reaction (HER) and the need for advanced catalyst and electrode designs. The review begins with a discussion on the mechanistic understanding of the reaction pathway, emphasizing the role of proton sources and the formation of key intermediates. It then delves into recent advancements in catalyst design, including heterogeneous catalysts, surface-immobilized molecular catalysts, and catalyst surface enhancements. The performance of these catalysts is evaluated based on current density, product type, Faradaic efficiency (FE), stability, and experimental conditions. The article highlights the importance of optimizing the local reaction environment, such as surface pH and cation concentration, to enhance CO₂RR activity and selectivity. It also addresses the degradation of catalysts in acidic media, particularly the dissolution and agglomeration of non-noble metal catalysts. Finally, the review outlines the challenges and future directions in the design of acidic CO₂RR catalysts, emphasizing the need for improved selectivity, activity, stability, and scalability. The article concludes by discussing the potential of single-atom catalysts (SACs) and metal-organic frameworks (MOFs)/open-frameworks (COFs) in achieving these goals.The article reviews recent advancements in the electrochemical reduction of CO₂ (CO₂RR) under acidic conditions, addressing the "carbonate issue" that arises in neutral or alkaline electrolytes. The "carbonate issue" refers to the formation of (bi)carbonate byproducts, which reduces the overall carbon utilization efficiency and complicates device-level applications. Conducting CO₂RR in acidic electrolytes offers a promising solution, but it presents challenges due to the enhanced hydrogen evolution reaction (HER) and the need for advanced catalyst and electrode designs. The review begins with a discussion on the mechanistic understanding of the reaction pathway, emphasizing the role of proton sources and the formation of key intermediates. It then delves into recent advancements in catalyst design, including heterogeneous catalysts, surface-immobilized molecular catalysts, and catalyst surface enhancements. The performance of these catalysts is evaluated based on current density, product type, Faradaic efficiency (FE), stability, and experimental conditions. The article highlights the importance of optimizing the local reaction environment, such as surface pH and cation concentration, to enhance CO₂RR activity and selectivity. It also addresses the degradation of catalysts in acidic media, particularly the dissolution and agglomeration of non-noble metal catalysts. Finally, the review outlines the challenges and future directions in the design of acidic CO₂RR catalysts, emphasizing the need for improved selectivity, activity, stability, and scalability. The article concludes by discussing the potential of single-atom catalysts (SACs) and metal-organic frameworks (MOFs)/open-frameworks (COFs) in achieving these goals.