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The loading of SACs by wet chemistry methods depends greatly on the density of anchoring sites on the support, and it is usually low. To circumvent the limitation, pyrolysis (i.e. treatment at high temperatures under inert gas) of molecularly defined porous structures containing both the source of metal and carbon can lead to higher loadings. In fact, it would be interesting if the porous structure is retained in the final carbon material. Otherwise, a sacrificial template can be used to preserve the porosity upon pyrolysis. Metal–organic frameworks (MOFs; see Chapter 8 for more details), composed of periodic and porous networks of organic linkers with metal atom centers, are an excellent platform to prepare single‐site catalysts on porous carbon in one‐step pyrolysis. This approach has been used to attain transition‐metal single sites on nitrogen‐doped carbon [47].