Unlocking CO2 Reduction: The Power of Porous Nanocages and Carbon Partners

Tiny cages made of molecules, called bis-porphyrin nanocages. These cages have metals like iron, cobalt, or zinc at their core. Scientists used these cages to see how their tiny pores and interactions with carbon nanomaterials affect their ability to turn CO2 into CO. These cages can stick to carbon black, making them great for conducting electricity even when there's a lot of metal inside. This is crucial for reducing CO2 efficiently. One interesting find was that when a molecule called C70 was trapped inside an iron-based cage, it could produce high amounts of CO at low energy costs. This happened with over 95% efficiency. Another cage, made with cobalt, also showed impressive results, turning over 1300 times per hour with 90% efficiency. This all happened at a specific energy level.Here's where it gets tricky. When the pores of the cages were blocked with C60 or C70, the iron-based cage's performance improved. This suggests that the cages' internal pores aren't the key to their good catalytic properties. It's like having a secret ingredient that isn't what you thought it was. The improvement in performance isn't due to faster electron transfer or special interactions between the metal and the carbon. This is different from what's often seen with other carbon supports. So, what's really going on here? It's a mystery that scientists are still trying to solve. Let's think about this. If these nanocages can reduce CO2 so efficiently, what other applications could they have? Could they help in making fuels or other useful chemicals? The possibilities are endless. The study also raises questions about how we understand these processes. If the pores aren't the key, what is? Understanding this could lead to even better catalysts in the future.