Conversion of CO2 into useful chemicals has been regarded as one promising method to mitigate the problem of global warming. However, developing an efficient method for CO2 reduction with facile hydrogen source is still a great challenge. In this study, a new and straightforward method to convert NaHCO3, a model compound of CO2 in basic solution, into formate with 2‐pyrrolidone, a model compound of protein‐containing biomass, as the reductant on a Pd/C catalyst in water was proposed. Results showed that a formate yield up to 30% from bicarbonate was successfully obtained over the Pd/C catalyst, and the Pd/C catalyst exhibited good catalytic activity and stability. Detailed studies revealed that the propanol generated from the decomposition of 2‐pyrrolidone under hydrothermal conditions acted as the actual reductant and hydrogen source for the bicarbonate reduction to formate. Since 2‐pyrrolidone can be readily generated from the proteins contained in biomass, the present research provides a promising technology of NaHCO3 reduction with biomass as the hydrogen source and the renewable energy input, thus it is green, sustainable, and promising for practical application.