We present a successive microfluidic approach to create and characterize hierarchical catalyst structures consisting of metal-decorated nanoparticles that are assembled into porous microparticles ("supraball" catalysts). First, using a silicon microreactor, platinum nanoparticles with a very narrow size distribution are grown and immobilized uniformly onto iron oxide/silica core-shell nanospher...

Nature is a valuable source of inspiration in the design of catalysts, and various approaches are used to elucidate the mechanism of hydrogenases, the enzymes that oxidize or produce H2. In FeFe hydrogenases, H2 oxidation occurs at the H-cluster, and catalysis involves H2 binding on the vacant coordination site of an iron centre. Here, we show that the reversible oxidative inactivation of this ...

Nanostructured carbon-based materials, such as nitrogen-doped carbon nanotube arrays, Co3O4/nitrogen-doped graphene hybrids and carbon nanotube-graphene complexes have shown respectable oxygen reduction reaction activity in alkaline media. Although certainly promising, the performance of these materials does not yet warrant implementation in the energy conversion/storage devices utilizing basic...

Acceptorless dehydrogenation of alcohols, an important organic transformation, was accomplished with welldefined and inexpensive iron-based catalysts supported by a cooperating PNP pincer ligand. Benzylic and aliphatic secondary alcohols were dehydrogenated to the corresponding ketones in good isolated yields upon release of dihydrogen. Primary alcohols were dehydrogenated to esters and lactone...

Use of hydrogen in fuel cells requires catalysts that are tolerant to oxygen and are able to function in the presence of poisons such as carbon monoxide. Hydrogen-cycling catalysts are widespread in the bacterial world in the form of hydrogenases, enzymes with unusual active sites composed of iron, or nickel and iron, that are buried within the protein. We have established that the membrane-bou...

In meeting the need for environmental remediation in wastewater treatment and the development of popular sulfate-radical-based advanced oxidation processes (SR-AOPs), a series of Co/Fe-based catalysts with confirmed phase structure were prepared through extended soft chemical solution processes followed by atmosphere-dependent calcination. Powder X-ray diffraction (XRD), scanning electron micro...

Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal-organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and r...

The Fischer-Tropsch synthesis (FTS) has been recognized as a heterogeneous surface-catalyzed polymerization process. During this process, CHx monomers formed via the hydrogenation of adsorbed CO on transition metals produce hydrocarbons and oxygenates with a broad range of chain lengths and functional groups. A series of Fe/Cu Fischer-Tropsch synthesis catalysts incorporated with a calcium prom...

The application of a variety of iron complexes with chelating amine ligands as pre-catalysts in the representative cross-coupling of 4-tolylmagnesium bromide with cyclohexyl bromide was investigated. The results from this study indicate the performance of the pre-catalyst is inversely proportional to the strength of the chelate or macrocyclic effect of the amine ligand, as determined by the pro...

Iron oxide microtubules produced by a species of iron-oxidizing bacteria, Leptothrix ochracea, have been expected to be useed as unique multifunctional materials such as catalysts scaffolds, pigments, and magnetic materials. However, their structural characteristics and formation mechanism are still ambiguous. The detailed features of the microtubules were characterized through electron microsc...