Whereas pyrolysis of pristine microcrystalline cellulose spheres yields nonporous amorphous carbon bodies, pyrolysis of microcrystalline cellulose spheres loaded with iron salts leads to the formation of magnetically separable mesoporous graphitic carbon bodies. The microcrystalline cellulose spheres loaded with either iron(III) nitrate, ammonium iron(III) citrate or iron(III) chloride were pyrolyzed up to 800 °C. Temperature dependent X-ray diffraction analysis shows that the iron salts are transformed into iron oxide nanoparticles; their size and distribution are influenced by the anion of the iron salt. The iron oxide nanoparticles are subsequently carbothermally reduced by the amorphous carbon that is obtained from the pyrolysis of the microcrystalline cellulose. Next, the iron nanoparticles catalyze the conversion of the amorphous carbon to graphitic carbon nanostructures as shown with XRD, electron microscopy and Raman spectroscopy. The extent of graphitization depends on the iron nanoparticle size. Nitrogen physisorption measurements show that this graphitization process introduces mesopores into the carbon bodies. The benefits of the properties of the resulting carbon bodies (ferromagnetic character, graphitic content, mesoporosity) are discussed in connection with applications in liquidphase catalysis and remediation.

A series of iridium-based complexes have been evaluated in Ce(IV)-driven water oxidation catalysis. Detailed kinetic data have been obtained from UV−vis stopped-flow experiments, and these data have been analyzed using reaction progress kinetic analysis. The graphical plots show that there are three clear phases in the reaction: catalyst activation, water oxidation catalysis, and cerium concentration controlled catalysis at the end of the reaction. The ligand attached to the IrCp* complex has a clear influence on both the activation as well as the catalysis. Some bidentate ligands result in relatively slow catalysis, and the first-order in iridium supports the presence of mononuclear active species; however, other bidentates form the more active dinuclear species. Monodentate ligands allow the formation of bis-μ-oxo bridged dimeric species, supported by kinetics displaying 1.6-order in [Ir], leading to high reaction rates.

Through designing the precursor complex, single Ir atoms can be selectively accommodated in hybrid materials, providing higher stability and activity in electrocatalysis.