Extending the CO2 Value Chain: Formic Acid as a Bridge Chemical Toward a Net-Zero Circular Carbon Economy

Reaching net-zero emissions requires more than displacing fossil combustion with renewable electricity; several of the largest industrial emitters—cement, steel, chemicals, and aviation—cannot be fully electrified with current technology, and captured carbon dioxide (CO2) itself must find a productive destination rather than remain a permanent liability. Converting CO2 into formic acid (HCOOH) has emerged as one of the more mature answers to that second problem. Formic acid combines a respectable hydrogen content (4.4 wt%), a stable liquid state at ambient conditions, and comparatively benign handling relative to gaseous or cryogenic hydrogen, positioning it as both a chemical feedstock and an energy carrier. This review synthesizes the current state of CO2-to-HCOOH conversion across thermochemical, electrochemical, photocatalytic, and biocatalytic routes; examines formic acid’s performance as a liquid organic hydrogen carrier (LOHC) and direct fuel-cell fuel; and evaluates the technology through a recently published pilot-scale case study of a photocatalytic reactor, branded RK-X, developed by the author’s employer—presented here as a single illustrative example rather than a representative benchmark—to show both the promise and the unresolved energetic and economic questions still facing the field. We conclude that formic acid-based CO2 utilization is technically credible and policy-relevant, but that claims of net energy or carbon benefit must be assessed pathway-by-pathway, powered overwhelmingly by low-cost renewable electricity, and confirmed through independent life-cycle assessment before the technology can be considered a settled pillar of the net-zero toolkit.