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An interview with Javier Pérez-Ramírez, full professor of catalysis engineering at ETH Zurich in Switzerland, is presented. Topics discussed include the main challenges for the future of catalytic materials, his thoughts about catalysis digitalization, and development of science and technology needed to obtain catalytic materials from feedstocks on which people can rely forever with zero environmental impact.

The article discusses the first large-scale preparation of hierarchically structured zeolite catalysts aimed at reproducibly introducing extensive intracrystalline mesoporosity into ZSM-5. Controlled silicon extraction in alkaline medium was done on a zeolite at laboratory, middle and pilot scales. It cites the successful demonstration of a large-scale preparation of hierarchical zeolites which clearly established the robustness of the desilication route.

Porous MnO2 microspheres distributed around magnetic carbon-coated cobalt nanoparticles were developed. The performance of these nanoparticles rivals that of Pd-based catalysts for the selective oxidation of alcohols. Excellent recyclability was conveniently achieved by magnetic decantation and is demonstrated in ten consecutive cycles with no apparent material or performance losses. [ABSTRACT FROM AUTHOR]

Catalysts based on individual precious metals on carbon‐ and oxide‐based carriers have shown remarkably selective behavior in the hydrodebromination of CH2Br2 to CH3Br, an important transformation within halogen‐mediated methane upgrading processes. However, the high susceptibility of the active phase to coking and to sintering, which cannot be overcome by controlling the nuclearity of the metal species, hinders their practical implementation. Herein, a platform of carbon‐supported Ir−Ru catalysts with distinct metal ratios at comparable metal nanoparticle size (ca. 1.0 nm) was adopted to systematically study the effects of a second metal on reactivity and stability. Catalytic tests reveal ruthenium‐doped iridium nanoparticles as the first system that combines high CH3Br selectivity (up to 93 %) with unprecedented stability, outperforming any of the previously reported catalysts. This superior performance was rationalized by the intimate interaction between the two metals, forming ruthenium‐poor surface alloys, which enable suppressing deactivation mechanisms as well as over hydrogenation/coking pathways. [ABSTRACT FROM AUTHOR]

Partial hydrogenation of unsaturated hydrocarbons comprises an important family of reactions that are applied in many industrial sectors. Understanding the hydrogenation of polyunsatured and polyunsaturated compounds on heterogeneous catalysts at its molecular level remains a challenging milestone to fine-tune the product distribution. Our study presents a detailed mechanistic analysis of the gas phase hydrogenation of vinylacetylene (1-butene-3-yne) and valylene (2-methyl-1-butene-3-yne) over palladium and copper catalysts. These two metals are selected owing to their pronounced differences in continuous flow catalytic tests at ambient pressure. The chemoselectivity, regioselectivity, isomerization, and oligomerization patterns measured in a broad range of feed hydrogen/hydrocarbon ratios are rationalized by density functional theory simulations. An extended Brønsted-Evans-Polanyi relationship for both substrates and active metals is found for the hydrogenation processes. The identified factors that govern selectivity are similar to those identified for smaller C2 and C3 compounds and, thus, a means of systematization to other polyunsaturated compounds is opened up. [ABSTRACT FROM AUTHOR]

Nanostructuring earth‐abundant metals as single atoms or clusters of controlled size on suitable carriers opens new routes to develop high‐performing heterogeneous catalysts, but resolving speciation trends remains challenging. Here, we investigate the potential of low‐nuclearity iron catalysts in the continuous liquid‐phase semi‐hydrogenation of various alkynes. The activity depends on multiple factors, including the nuclearity and ligand sphere of the metal precursor and their evolution upon interaction with the mesoporous graphitic carbon nitride scaffold. Density functional theory predicts the favorable adsorption of the metal precursors on the scaffold without altering the nuclearity and preserving some ligands. Contrary to previous observations for palladium catalysts, single atoms of iron exhibit higher activity than larger clusters. Atomistic simulations suggest a central role of residual carbonyl species in permitting low‐energy paths over these isolated metal centers. [ABSTRACT FROM AUTHOR]

Metal‐free carbon catalysts represent attractive alternatives to platinum and chromium‐containing systems for the on‐purpose production of propylene, a crucial chemical building block, via non‐oxidative propane dehydrogenation. However, the role of heteroatoms in determining reactivity and stability is poorly understood. Here, the study of a platform of polyaniline‐derived and activated carbons, with distinct porous properties, and heteroatom type, content, and speciation, enables establishing improved structure‐performance relationships. In‐depth characterization reveals that, while several oxygen species potentially catalyze the reaction, carbonyl groups are the main functionality governing the activity. Oxygen loss via propane‐driven water evolution is the main deactivation path. Six‐fold enhanced stability evidenced over carbon catalysts derived from KOH‐post‐treated polyanilines demonstrates the importance of controlling the nanostructure for enhancing longevity. [ABSTRACT FROM AUTHOR]

Developing efficient solid catalysts is necessary when for example moving from batch chemistry to continuous flow systems. In this work, scale‐up effects of zeolite‐based catalyst materials have been tested in aldol condensation as a model reaction for bio‐oil upgrading via deoxygenation. For this purpose, shaped catalyst bodies were obtained via extrusion of ultrastable Y zeolite (USY) using either attapulgite (Att.) or bentonite (Bent.) as clay binder, followed by post‐alkali metal ion grafting of K+ after (rather than before) extrusion. This approach proved essential to preserve the catalysts' crystallinity. The Att.‐bound catalyst body was more active than its Bent.‐counterpart, correlating well with the observed changes in physicochemical properties. The K‐(USY/Att.) catalyst showed new basic oxygen and strong Lewis acidic sites resulting from clay incorporation, in addition to the Lewis acid (K+) and basic sites (K−OH) created upon grafting. For K‐(USY/Bent.), the grafting proved less efficient, likely due to pore blockage caused by the binder. Bent. addition resulted in acid sites of moderate Brønsted and strong Lewis acidity, but hardly any of the basicity desired for the aldol condensation reaction. The poor potassium grafting yet led to some cation exchange with the binder (likely with the Na+ naturally present in the Bent. material). The results obtained demonstrate the critical importance of the choice of the binder material and the synthesis protocol adopted for upscaling solid base materials in the form of catalyst bodies. [ABSTRACT FROM AUTHOR]

Converting syngas obtained from renewable or abundant feedstocks into higher alcohols (HA) is a potentially more sustainable route to these important chemicals and fuels than industrial technologies, but lacks a performing catalytic process to reach commercialization. Here, we show that moderate CO2 amounts (R=CO2/(CO+CO2)=0.12) in the feed raise the HA productivity over copper‐iron catalysts carried on carbon nanofibers and promoted by potassium to a 3‐fold higher level than the state of the art. CO2 promotes copper dispersion and thus the formation of activated CO species, as in traditional methanol synthesis. Still, since its vicinity to iron is boosted, CO insertion into growing hydrocarbon chains prevails on hydrogenation, translating positive effects to HA production. Cascade zeolite‐catalyzed upgrading of methanol and olefins byproducts generates a breakthrough process forming 2.42 gHA h−1 gcat−1, which is 4‐times superior to the best systems, and tuning the HA nature based on the aluminosilicate topology. [ABSTRACT FROM AUTHOR]

Porous nitrogen‐doped carbons (NCs) are sustainable alternatives to the toxic mercury‐based acetylene hydrochlorination catalysts applied in the manufacture of polyvinyl chloride. However, the application of NCs as metal‐free catalysts is hampered by their insufficient durability under industrially relevant process conditions. In particular, pore blockage leads to accelerated deactivation of NCs compared to the state‐of‐the‐art precious metal‐based systems. Herein, we develop a salt template‐assisted synthesis strategy coupled with chemical blowing to tune the textural properties of NCs, while preserving the N‐content and speciation. The addition of metal salts (i. e. Mg(OAc)2 or CaCO3) enhances gas evolution, leading to an increased formation of micro‐ and mesopores, while the in‐situ generated CaO/CaCl2 and MgO/MgCl2 develop auxiliary pore networks. Micropores are easily blocked during acetylene hydrochlorination, but meso‐ and macropores are structurally stable, enhancing the lifetime of hierarchical NCs by ca. 50 times compared to their non‐templated analogues, rivaling the stability of benchmark metal‐based catalysts. [ABSTRACT FROM AUTHOR]

The application of nitrogen-doped carbons (NDCs) as host materials for single-atom catalysts (SACs) is increasing because of the strong binding affinity of the heteroatom with transition metals. Establishment of the relation between the properties of NDCs, their interaction with metals, and the performance of the resulting catalysts is crucial to guide the design of more effective SACs but has not been critically addressed. Here, a series of NDCs is prepared and studied as hosts for palladium atoms. The amount of nitrogen incorporated primarily depends on the choice of carbon followed by the doping temperature and nitrogen source. Pyridinic and pyrrolic species predominate in all cases, especially at lower doping temperatures. The stabilization of palladium atoms is successful above a critical nitrogen content that depends on the carbon type. Evaluation in the catalytic semi-hydrogenation of 2-methyl-3-butyn-2-ol readily distinguishes the reactivity of single atoms and nanoparticles, which correlates with the electronic properties of palladium described by the average oxidation state. Comparison with SACs based on compositionally-related carbon nitride hosts shows that similarly high stability and tunability of the metal is achievable over NDCs, despite their lower nitrogen contents and greater heterogeneity of coordination sites. [ABSTRACT FROM AUTHOR]

Modification of transition metals with p‐block elements is known to be effective to tune the ensemble characteristics of catalysts for the semi‐hydrogenation of alkynes. To further explore this approach, here we prepare two nickel phosphides, namely Ni2P and Ni5P4. Assessment in the semi‐hydrogenation of 1‐hexyne and 2‐methyl‐3‐butyn‐2‐ol shows that the phosphides present higher rate and selectivity than unmodified nickel catalysts. While no activity and selectivity differences are displayed in the semi‐hydrogenation of 1‐hexyne over Ni2P and Ni5P4, in the case of 2‐methyl‐3‐butyn‐2‐ol a higher rate and lower selectivity to 2‐methyl‐3‐buten‐2‐ol are observed over Ni2P. Density functional theory reveals that the hydroxyl group facilitates the reaction, but also increases the barrier for product desorption. Detailed analyses of the ensemble show the potential of phosphorus to create spatially‐isolated nickel trimers that surpass the performance of unmodified nickel, but also its limited ability to modulate the electronic properties and related binding energies of organic intermediates, which is key to preventing undesired side reactions. No limit! By exploring the effect of phosphorus on the ensemble properties of nickel phosphide catalysts, the scope of this design strategy for alkyne semi‐hydrogenation catalysts is delimited. [ABSTRACT FROM AUTHOR]

Abstract: Alkane oxyhalogenation has emerged as an attractive catalytic route for selective natural gas functionalization to important commodity chemicals, such as methyl halides or olefins. However, few systems have been shown to be active and selective in these reactions. Here, we identify a novel and highly efficient TiC–SiC composite for methane and ethane oxyhalogenation. Detailed characterization elucidates the kinetics and mechanism of the selective activation under reaction conditions to yield TiO2–TiC–SiC. This catalyst outperforms bulk TiO2, one of the best reported catalysts, reaching up to 85 % selectivity and up to 3 times higher titanium‐specific space‐time‐yield of methyl halides or ethylene. This is attributed to the fact that the active TiO2 phase generated in situ is embedded in the thermally conductive SiC matrix, facilitating heat dissipation thus improving selectivity control. [ABSTRACT FROM AUTHOR]

The establishment of suitable processes for the conversion of glycerol into allyl alcohol is hindered by the fast deactivation of solid acids in the dehydration of the substrate to acrolein and by the requirement of hydrogen donors to enhance the selectivity of the subsequent reduction step. In this work, silver nanoparticles deposited onto a hierarchical ZSM-5 zeolite are proved to be an effective bifunctional catalyst to conduct the two reactions in the gas phase and in the presence of hydrogen by using a continuous fixed-bed reactor. The acidic function was accomplished by using a ZSM-5 zeolite modified by facile alkaline and acid treatments, which decreased the amount of Lewis acid centers while preserving the amount of Brønsted acid centers, and introduced an auxiliary network of intracrystalline mesopores, thus boosting the selectivity to acrolein (62 %) and the resistance to coking. Upon screening of various metals supported on the aluminosilicate, silver was identified as a superior hydrogenation catalyst, enabling a relatively high activity with >50 % allyl alcohol selectivity. Tuning of the metal loading, temperature, pressure, and contact time led to 15 % yield of allyl alcohol, thus approaching the state-of-the-art transfer hydrogenation systems, and stable behavior for 100 h on stream. Our results highlight the advantage of conducting the two transformations over a bifunctional material rather than over two separate single-function solids. [ABSTRACT FROM AUTHOR]

Furan derivatives, such as 5-hydroxymethylfurfural (HMF) and furfural, obtained from renewable feedstocks are sustainable alternatives to petroleum-based building blocks for the manufacture of chemical products. This study shows for the first time the applicability of the catalytic fast pyrolysis (CFP) of glucose over tailored zeolites for the production of HMF and furfural. In particular, we demonstrate that Lewis-acid-containing faujasite zeolites attained by alkali metal-cation exchange exhibit combined yields to these platform molecules of 17 %. Despite the fact that further research is required on the process assessment at a larger scale and under more realistic conditions, CFP has potential for the production of biomass-derived commodity chemicals. [ABSTRACT FROM AUTHOR]

Nanoparticles are applied in a variety of industrially relevant transformations as heterogeneous catalysts typically with the help of an external force (pressure, temperature, or voltage) to steer the chemistry. The modification of platinum nanoparticles by a phosphate-amino surfactant enables catalysis without external energy supply in the hydrogenation of nitrobenzene to aniline. This can be attributed to the complex surfactant/metal interface which is able to split hydrogen into protons and electrons. The subsequent hydrogenation process mimics the electrochemical reduction described by Haber. The surfactant decorated Pt catalyst is two orders of magnitude more active than the state-of-the-art Pb-poisoned Pt catalyst. Our study provides a new approach to understand the functionality of emerging catalytic systems and can be applied to design new materials with optimal interfaces. [ABSTRACT FROM AUTHOR]

The Cover shows a hierarchically structured MnO2‐Co/C nanocomposite developed as a magnetically recoverable catalyst for the aerobic oxidation of alcohols. In their Communication, Zhi et al. demonstrate that these hybrid systems offer high catalytic activity, outperforming traditional oxidation systems using MnO2 as oxidant and rivalling the activity of Pd‐based catalysts, in addition to convenient separation by external magnets and excellent recyclability. More details can be found in the Communication by Zhi et al. on page 2585 in Issue 17, 2015. (DOI: 10.1002/cctc.201500549). [ABSTRACT FROM AUTHOR]

The industrial viability of heterogeneous catalysts for the gas-phase conversion of lactic acid to acrylic acid will strongly depend on their selectivity and durability. Here, we initially screened various aluminum-rich zeolites confirming that NaY is the most efficient catalyst for this reaction. This material was modified by sequential dealumination and alkaline treatment attaining a solid featuring a hierarchical distribution of micro- and mesopores, reduced Lewis acidity, and increased basicity owing to the presence of well-dispersed sodium ions interacting with external siloxy groups, as evidenced by in-depth characterization. These properties were crucial for determining higher selectivity (75 %) and minimizing the activity loss in a 6 h run. Remarkably, the catalyst gained in selectivity and stability upon reuse in consecutive cycles. This was ascribed to the depletion of the stronger basic sites and the clustering of sodium into oxidic particles upon the intermediate calcination. [ABSTRACT FROM AUTHOR]

Selective hydrogenations lay at the heart of many industrial processes. The archetypal catalysts for this class of reactions are generally prepared by 'metal poisoning' strategies: the active metal is protected and selectively deactivated with various compounds. This approach has been applied for decades, with limited understanding. Low product selectivity and presence of toxic elements in the catalyst pose severe constraints in the utilization of these materials in the future. Thus, to develop more sustainable catalysts, this field has recently gained momentum. This Review analyzes the concepts and frontiers that have been developed in the last decade: from nanostructuring less conventional metals in order to improve their ability to activate H2, to the use of oxides as active phases, from alloying, to the ensemble control in hybrid materials, and site isolation approaches in single-site heterogeneous catalysts. Particular attention is given to the hydrogenation of alkynes and nitroarenes, two reactions at the core of the chemical industry, importantly applied in the manufacture of polymers, pharmaceuticals, nutraceuticals, and agrochemicals. The strategies here identified can be transposed to other relevant hydrogenations and can guide in the design of more advanced materials. [ABSTRACT FROM AUTHOR]

The transfer hydrogenation of sugars to alditols with biobased alcohol donors was studied over hydrotalcite-derived Cu6− xNi xAl2 catalysts prepared by coprecipitation at different pH and featuring variable Cu/Ni ratios. Their evaluation, after in situ activation in pure H2 at 773 K, in the ethanol-assisted upgrading of glucose in a continuous-flow fixed-bed reactor identified the solid synthesized at pH 9-10 and with Cu/Ni=1 as the best performer. Based on textural, structural, and redox analyses, this is related to an enhanced intermetallic interaction. Upon screening alternative donors, a sorbitol yield as high as 67 % was achieved with 1,4-butanediol. The catalytic system displayed a stable behavior during 48 h on stream and proved suitable to hydrogenate also fructose, mannose, xylose, and arabinose to the corresponding polyols (yields up to 65 %), thus standing as a more sustainable and economical alternative to Ru-based catalysts for sugar reductive upgrading. [ABSTRACT FROM AUTHOR]

TiO2-, Al2O3-, and ZrO2-supported CeO2 catalysts with different Ce loadings were prepared by wet impregnation of the carriers with an acidified solution of cerium ammonium nitrate. The calcined catalysts were characterized by bulk and surface-sensitive techniques, which included microcalorimetry, and evaluated in the three-phase hydrogenation of alkynes under continuous-flow conditions at variable temperature (293-413 K) and pressure (1-90 bar). A number of acetylenic compounds, which contain terminal or internal triple bonds, conjugated unsaturations, and additional functionalities, were systematically assessed. The results revealed the full stereo- and chemoselective character of the ceria catalysts, which outperform the well-known Lindlar catalyst, and open promising perspectives for the revolutionary use of a cost-effective oxide for the production of olefinic compounds in the vitamin and fine chemical industries. [ABSTRACT FROM AUTHOR]

The gas-phase partial hydrogenation of propyne was investigated over supported Ag nanoparticles (2-20 nm in diameter) prepared by using different deposition methods, activation conditions, loadings, and carriers. The excellent selectivities to propene attained over the catalysts, exceeding 90 %, are independent of the particle size but the activity is maximal over approximately 4.5 nm Ag particles. Certain kinetic fingerprints of Ag, such as the positive dependence on the alkyne pressure, the relatively low reaction order in H2, and the low apparent activation energy, deviate from those of conventional hydrogenation metals such as Pd and Ni, questioning the applicability of the classical Horiuti-Polanyi scheme. Periodic dispersion-corrected density functional theory (DFT-D) calculations and microkinetic analysis demonstrate the occurrence of an associative mechanism, which features the activation of H2 on the adsorbed propyne at structural step sites. By using the atomistic Wulff model, the number of B5 sites available on the Ag nanoparticles was estimated to be maximal in the size range of 3.5-4.7 nm. The rate of propene production correlates with the density of B5 sites, which suggests that the latter are potential active centers for the reaction. This alternative pathway broadens the mechanistic diversity of hydrogenation reactions over metal surfaces and opens new directions for understanding metals that do not readily activate H2. [ABSTRACT FROM AUTHOR]

Making a quick recovery: The widespread implementation of bromination reactions to manufacture value‐added products is contingent upon the development of sustainable and cost‐effective means to recycle copious amounts of HBr byproduct. We report families of heterogeneous catalysts for the full recovery of Br2 through HBr oxidation that display unprecedented low‐temperature activity and stability. [ABSTRACT FROM AUTHOR]

In their Communication, A. J. Saadun et al. study bimetallic systems of distinct composition and equivalent nanoparticle size, showing that the formation of dilute ruthenium alloys with iridium suppresses deactivating overhydrogenation or coking pathways observed on the respective monometallic systems. Bimetallic catalysts, hydrodebromination, iridium, nanoparticles, ruthenium Keywords: bimetallic catalysts; hydrodebromination; iridium; nanoparticles; ruthenium EN bimetallic catalysts hydrodebromination iridium nanoparticles ruthenium 1 1 1 01/25/22 20220121 NES 220121 B The Cover Feature b shows a bimetallic Ir-doped Ru nanoparticle supported on carbon with unprecedented selective and stable character in the hydrodebromination of dibromomethane to bromomethane. [Extracted from the article]

RuO2/SnO2-Al2O3 has been recently reported as an industrial catalyst for Cl2 production through HCl oxidation. The stabilizing role of the alumina binder in the material, essential for its durable performance, is elucidated here. Al2O3 prevents chlorination of the SnO2 carrier under relevant reaction conditions, whereas, in its absence, SnO2 losses exceed 80 wt % in very short times owing to volatilization as SnCl4. Characterization by using X-ray diffraction, temperature-programmed reduction with hydrogen, and high-resolution TEM indicates expansion of the cassiterite cell in the SnO2-Al2O3 composite with respect to pure SnO2, which suggests the insertion of certain Al species upon mechanochemical and thermal activation of the oxide mixture. 27Al magic-angle spinning NMR and X-ray photoelectron spectroscopy studies reveal that the pentahedrally coordinated Al3+ cations interact with SnO2, generating an electron-depleted region near the surface of SnO2 particles. This induces some acidic character in cassiterite, which possibly makes it inert toward HCl. Besides this electronic effect, the presence of thin porous amorphous alumina films, partly covering the SnO2 surface, can offer additional geometric protection of the support. Mechanical mixing followed by calcination is essential to attain stabilization, and maximized effects are achieved with a high-surface area alumina. Other oxides such as SiO2 are ineffective in preventing tin losses during HCl oxidation. The practical implications of these findings are very important. The metal loading (fourfold decrease) and, thus, the cost of the catalyst can be significantly lowered without compromising its long-term stability. [ABSTRACT FROM AUTHOR]

We present 100 % selectivity to p-chloroaniline through the continuous gas-phase (atmospheric pressure; T=393-523 K) catalytic hydrogenation of p-chloronitrobenzene over an activated CuAl (molar Cu/Al ratio 3:1) hydrotalcite. The synthesis by continuous co-precipitation and application of a CuNiAl (atomic Cu/Ni/Al ratio 2.75:0.25:1) catalyst is also described. Temperature-programmed reduction in hydrogen and XPS analyses of the ternary catalyst suggest CuNi interaction with no evidence of (bulk) alloy formation (based on XRD). Under the same reaction conditions, CuNiAl exhibited a higher (by up to a two-fold) hydrogenation rate when compared to CuAl, while the exclusive nitro-group reduction was maintained. [ABSTRACT FROM AUTHOR]

Alkyne hydrogenation, Iron catalysts, Nuclearity effects, Single atoms, Carbon nitride Cover Feature: Precursor Nuclearity and Ligand Effects in Atomically-Dispersed Heterogeneous Iron Catalysts for Alkyne Semi-Hydrogenation (ChemCatChem 14/2021) Keywords: Alkyne hydrogenation; Iron catalysts; Nuclearity effects; Single atoms; Carbon nitride EN Alkyne hydrogenation Iron catalysts Nuclearity effects Single atoms Carbon nitride 3199 3199 1 07/30/21 20210721 NES 210721 B The Cover Feature b depicts different single-atom species stabilized from iron pentacarbonyl on graphitic carbon nitride and their distinct selective hydrogenation activity (shown by the color of the light stream). [Extracted from the article]

Keywords: propane dehydrogenation; metal-free catalysis; heteroatom-doped carbons; propylene; structure-performance relationships EN propane dehydrogenation metal-free catalysis heteroatom-doped carbons propylene structure-performance relationships 2540 2540 1 06/10/21 20210608 NES 210608 B The Cover Feature b shows a high-speed train, representing non-oxidative propane dehydrogenation, running on a monorail connected to specific atoms (active sites) on a catalyst surface. Propane dehydrogenation, metal-free catalysis, heteroatom-doped carbons, propylene, structure-performance relationships Cover Feature: Impact of Heteroatom Speciation on the Activity and Stability of Carbon-Based Catalysts for Propane Dehydrogenation (ChemCatChem 11/2021). [Extracted from the article]

Front Cover: CO2-Promoted Catalytic Process Forming Higher Alcohols with Tunable Nature at Record Productivity (ChemCatChem 10/2020) Keywords: higher alcohols synthesis; CO2 promotion; copper-iron; hydrogenation; zeolite upgrading EN higher alcohols synthesis CO2 promotion copper-iron hydrogenation zeolite upgrading 2647 2647 1 05/23/20 20200520 NES 200520 The Front Cover shows a two-seater airplane emerging from a thin cloud up in the sky on a sunny day. Higher alcohols synthesis, CO2 promotion, copper-iron, hydrogenation, zeolite upgrading. [Extracted from the article]

Keywords: acetylene hydrochlorination; catalyst stability; hierarchical porosity; N-doped carbon; chemical blowing EN acetylene hydrochlorination catalyst stability hierarchical porosity N-doped carbon chemical blowing 1800 1800 1 04/10/20 20200406 NES 200406 B The Front Cover b shows hierarchically porous nitrogen-doped carbon (NC) as a durable catalyst for vinyl chloride production via acetylene hydrochlorination. The optimized metal-free catalyst exhibits a ca. 50 times slower deactivation rate compared to the purely microporous analog and rivals the stability of state-of-the-art metal-based catalysts. Acetylene hydrochlorination, catalyst stability, hierarchical porosity, N-doped carbon, chemical blowing. [Extracted from the article]

The Cover Feature is inspired by the signature screen prints of the pop‐artist Andy Warhol. The brightly colored repetitive images of cat mosaics represent the diverse possible geometric and electronic properties of ensembles of transition metals with p‐block elements, which ultimately determine their performance in the selective semi‐hydrogenation of C−C triple bonds. In their Full Paper, D. Albani et al. investigate the effect of phosphorus on the ensemble properties of distinct nickel phosphide catalysts, namely Ni2P and Ni5P4, for the three‐phase semi‐hydrogenation of alkynes. More information can be found in the Full Paper by D. Albani et al. on page 457 in Issue 1, 2019 (DOI: 10.1002/cctc.201801430). [ABSTRACT FROM AUTHOR]

The Cover shows how rENewable ‐ based processes challENge existing oil ‐ based routes for a more sustainable manufacture of consumer products. The establishmENt of alternative technologies is contingENt upon the idENtification of effective heterogENeous catalysts and suitable feedstocks. In their Full Paper, G.   M. Lari, B. Puértolas et   al. describe the design of a zeolite ‐ based catalyst for the gas ‐ phase transformation of lactic acid, a versatile platform easily obtained from glycerol or sugars, into acrylic acid, a commodity chemical used in paints, plastics, glues, and superabsorbENts. Simple and scalable acid and alkaline treatmENts ENable the introduction of basicity and mesoporosity and the reduction of Lewis acidity in a commercial aluminosilicate, gENerating a material that shows superior selectivity and remarkably ENhanced stability. More information can be found in the Full Paper by G.   M. Lari, B. Puértolas et   al. on page   1507 in Issue 8, 2016 (DOI: 10.1002/cctc.201600102). [ABSTRACT FROM AUTHOR]

The front cover picture shows the give‐and‐take concept at the basis of a continuous transfer‐hydrogenation process for the reductive upgrading of renewable substrates. In their Full Paper Pérez‐Ramírez and co‐workers describe how the accurate selection of the catalyst precursor and metal ratio is key to generate a CuNiAl catalyst for the efficient and stable conversion of hexoses and pentoses to alditols. This heterogeneous catalyst is also able to transform suitable dehydrogenated alcohols by lactonization, thus obtaining additional relevant chemical intermediates in the same process. This system stands as a sustainable technology for the valorization of saccharide feedstocks in future biorefineries. More information can be found in the Full paper by Pérez‐Ramírez and co‐workers. The article highlighted by this cover can be found on p. 1551 ff. of Issue 10, 2015. [ABSTRACT FROM AUTHOR]

The front cover artwork for Issue 10/2015 is provided by the group of Prof. Javier Pérez-Ramírez at the ETH Zurich. The cover depicts the give-and-take concept at the heart of an emerging continuous transfer hydrogenation process for the conversion of sugars to alditols. See the Full Paper itself at . [ABSTRACT FROM AUTHOR]

Stability is the key! The cover picture shows the technical RuO2/SnO2‐Al2O3 catalyst (2 mm pellets) for the gasphase oxidation of HCl to Cl2. This reaction is an attractive route to valorise byproduct HCl streams in the chemical industry and has been experiencing a strong revival since recent discoveries of durable catalytic materials have broken through to pilot and plant scales. In their Full Paper on p. 748 ff., J. Pbrez‐Ramrez, T. Schmidt, and co‐workers reveal the stabilizing effect of the nanocrystalline alumina binder on the tin oxide support. The fundamental understanding of this stabilization secures the longevity of the industrial catalyst and has enabled a four‐fold decrease in the ruthenium content while maintaining a high specific activity. [ABSTRACT FROM AUTHOR]