Reduction of [11C]CO2 to [11C]CO using solid supported zinc

A new method for the reduction of no‐carrier‐added ¹¹C]carbon dioxide into ¹¹C]carbon monoxide (¹¹C]CO) is described, in which the reductant (zinc) is supported on fused silica particles. Using this setup, which allows for a reduction temperature (485°C) well above the melting point for zinc (420°C), radiochemical yields of up to 96% (decay‐corrected) were obtained. A slight decrease in radiochemical yield was observed upon repeated ¹¹C]CO productions (93 ± 3%, n  = 20). The methodology is convenient and efficient and provides a straightforward path to no‐carrier‐added production of ¹¹C]CO.