In this review, we discuss the phenomenon of complementary macropore incorporation into mesoporous and/or microporous solids in order to enhance their catalytic performance in fuels and chemicals synthesis.

Semihydrogenation of acetylene in an ethylene-rich stream is an industrially important process. Conventional supported monometallic Pd catalysts offer high acetylene conversion, but they suffer from very low selectivity to ethylene due to overhydrogenation and the formation of carbonaceous deposits. Herein, a series of Ag alloyed Pd single-atom catalysts, possessing only ppm levels of Pd, supported on silica gel were prepared by a simple incipient wetness coimpregnation method and applied to the selective hydrogenation of acetylene in an ethylene-rich stream under conditions close to the front-end employed by industry. High acetylene conversion and simultaneous selectivity to ethylene was attained over a wide temperature window, surpassing an analogous Au alloyed Pd single-atom system we previously reported. Restructuring of AgPd nanoparticles and electron transfer from Ag to Pd were evidenced by in situ FTIR and in situ XPS as a function of increasing reduction temperature. Microcalorimetry and XANES measurements support both geometric and electronic synergetic effects between the alloyed Pd and Ag. Kinetic studies provide valuable insight into the nature of the active sites within these AgPd/SiO2 catalysts, and hence, they provide evidence for the key factors underpinning the excellent performance of these bimetallic catalysts toward the selective hydrogenation of acetylene under ethylene-rich conditions while minimizing precious metal usage.

The classical strong metal–support interaction between TiO2 and IB metals was demonstrated.

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Dry reforming of methane (DRM) is an attractive route to utilize CO2 as a chemical feedstock with which to convert CH4 into valuable syngas and simultaneously mitigate both greenhouse gases. Ni-based DRM catalysts are promising due to their high activity and low cost, but suffer from poor stability due to coke formation which has hindered their commercialization. Herein, we report that atomically dispersed Ni single atoms, stabilized by interaction with Ce-doped hydroxyapatite, are highly active and coke-resistant catalytic sites for DRM. Experimental and computational studies reveal that isolated Ni atoms are intrinsically coke-resistant due to their unique ability to only activate the first C-H bond in CH4, thus avoiding methane deep decomposition into carbon. This discovery offers new opportunities to develop large-scale DRM processes using earth abundant catalysts.

Fischer–Tropsch synthesis (FTS) is a process which converts syn-gas (H2 and CO) to synthetic liquid fuels and valuable chemicals. Thermal gasification of biomass represents a convenient route to produce syn-gas from intractable materials particularly those derived from waste that are not cost effective to process for use in biocatalytic or other milder catalytic processes. The development of novel catalysts with high activity and selectivity is desirable as it leads to improved quality and value of FTS products. This review paper summarises recent developments in FT-catalyst design with regards to optimising catalyst activity and selectivity towards synthetic fuels

Concern over the economics of accessing fossil fuel reserves, and widespread acceptance of the anthropogenic origin of rising CO2 emissions and associated climate change from combusting such carbon sources, is driving academic and commercial research into new routes to sustainable fuels to meet the demands of a rapidly rising global population. Here we discuss catalytic esterification and transesterification solutions to the clean synthesis of biodiesel, the most readily implemented and low cost, alternative source of transportation fuels to meet future societal demands.

The heterogeneously catalyzed aerobic selective oxidation of hydrocarbons offers new, environmentally benign routes to a diverse range of valuable intermediates for the pharmaceutical, fine chemical, and agrochemical sectors.[1] Such powerful catalytic technologies circumvent the use of stoichiometric reagents and expensive homogeneous complexes along with the associated process disadvantages and safety issues. [2] While there has been recent interest in the potential of gold as a partial oxidation catalyst, [3] such systems typically offer low oxygenate yields and require either radical initiators, [4] high temperatures, or high O 2 partial pressures.[5] Supported ruthenium, [6] palladium, and platinum clusters are also promising candidates to catalyze the selective oxidation (selox) of primary alcohols to their corresponding aldehydes under mild conditions. [7] These reactions are highly regioselective in the presence of diverse functionalities, including allylic groups. Most studies in this area employing Pd and Pt have utilized commercial formulations based upon amorphous carbon or oxide supports. However, the poor intrinsic performance of these materials relative to their homogeneous counterparts has often necessitated ad hoc promotion of the reaction by non-noble metals to achieve even moderate yields.[8] Two factors presently constrain the wider adoption of heterogeneous Pd selox catalysts amongst both academic and industrial communities: first, uncertainty over the active site responsible for the rate-limiting oxidative dehydrogenation step, [9] and second, the use of conventional supports with restrictive pore dimensions that inhibit efficient mass and heat transfer to and from reaction sites and limit the range of viable solvents and substrates. [10] Recent studies have implicated surface palladium oxide as the active center in allylic alcohol selox.[11] Since the energetics of metal clusters increasingly favor oxide-terminated surfaces with decreasing cluster size, [12] we hypothesized that a mesoporous high-area support would serve to both stabilize highly dispersed palladium oxide nanoparticles and would facilitate efficient alcohol and aldehyde diffusion. Herein, we report the successful synthesis of tailored PdAl 2 O 3 catalysts and demonstrate that extremely low palladium loadings generate atomically dispersed Pd II surface species that confer exceptional selox activity of allylic alcohols.Mesoporous alumina-supported palladium catalysts (Pd/ meso-Al 2 O 3 ) were prepared by a modified surfactant-templated route through hydrolysis of aluminum sec-butoxide and subsequent aging in the presence of lauric acid.[13] The organic template was removed by calcination prior to incipient wetness impregnation with tetraammine palladium(II) nitrate solution (see the Supporting Information). Samples were then calcined, reduced, and stored in air. Porosimetry and powder X-ray diffraction confirmed that the final processed materials possessed well-defined, hexagonal pore structures, with surface areas of 35...