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The free-standing Ni-Al2O3 ensemble derived from NiAl-layered double hydroxides (NiAl-LDHs) grown onto a Ni-foam has been developed for the exothermic gas-phase acetone hydrogenation to isopropanol. This approach works effectively and efficiently to achieve a unique combination of high activity/selectivity and enhanced heat/mass transfer stemmed from the Ni-foam. The outstanding catalyst is obtained by direct reduction of the un-calcined NiAl-LDH/Ni-foam, with a high turnover frequency of 0.90 s-1, being capable of converting 90.8% acetone into isopropanol with almost 100% selectivity under stoichiometric H2/acetone molar ratio, atmospheric pressure at 80 °C, and a WHSVacetone of 10 h-1. The catalyst derivation using the un-calcined NiAl-LDH/Ni-foam enables the Ni nanoparticles to be intertwined with Al2O3 to form a large Ni-Al2O3 interface, without interruption of impurities such as irreducible NiO (in the case of calcined NiAl-LDH/Ni-foam samples), which markedly improves the strong acetone adsorption next to the Ni0 hydrogenation sites, thereby leading to a dramatic improvement of catalyst activity.

Thin-felt ZSM-11/stainless-steel(SS)-fiber composites are successfully prepared via a combined washcoating and steam-assisted crystallization (SAC) method. Pre-aging of synthesis sol at a lower temperature of 80 °C can facilitate the zeolite nucleation and subsequent SAC growth at 180 °C. Such synthesis approach realizes the flexible tuning of acidity via adjusting SiO2/Al2O3 molar ratio in a wide range, including but not limited from 105 to 425. The as-synthesized ZSM-11/SS-fiber composites are employed as catalysts for the methanol-to-propylene reaction, and the promising thin-felt catalyst with SiO2/Al2O3 molar ratio of 200 shows remarkable stability improvement in comparison with its powdered counterpart, due to enhanced zeolite utilization efficiency and heat/mass transfer by the microfibrous-structured design.

Thin-sheet microfibrous-structured Pd–MgO–Al2O3/Al-fiber catalysts were developed for high-throughput catalytic methane combustion with 3–15 vol% water vapor in feed gas. The catalysts were obtained by hydrothermally growing Mg–Al mixed-oxide precursors (e.g., layered double hydroxides (LDHs) plus MgCO3) on Al-fiber surfaces followed by placing 0.5 wt% Pd on the as-obtained substrates by impregnation. Transformation of Pd/MgAl-LDH–MgCO3 mounted on the Al-fiber into Pd-MgO-Al2O3 via in situ reaction activation markedly enhances the catalyst basicity and electron density of metallic Pd, thus weakening support electrophilicity and stabilizing PdO against the formation of inactive Pd4+ species. This preferred catalyst with high intrinsic activity (turnover frequency 135 h−1 at 290 °C and 3 vol% water vapor) achieves a very low Ea of only 57 kJ mol−1, a third that (170 kJ mol−1) for the Pd/AlOOH/Al-fiber. This catalyst can stably run for feed gases of 1 vol% methane and 3–15 vol% water vapor in air.

Microfibrous-structured Pd/brass-fiber catalysts are developed for the selective hydrogenation of acetylene in the front-end configuration. The brass fibers are pre-calcined in air to create an endogenously growing ZnO-CuOx composite layer, and 0.25 wt% Pd is loaded on the brass fibers via the impregnation method. The activity and selectivity of our Pd/brass-fiber catalysts are primarily governed by the alloying degree of active sites regarded as Pd-Zn-Cu ensembles with the PdCu(alloy)-PdZnCu(alloy) twin structure, which are strongly sensitive to both the brass-fiber calcination and the catalyst reduction temperatures. For the preferred catalyst obtained using brass fibers calcined at 500 °C and reduced in H2 at 250 °C, over 90% selectivity is achieved at nearly 100% acetylene conversion with promising stability. Additionally, due to the weakened ethylene hydrogenation ability at high reaction temperature over the Pd-Zn-Cu ensembles, the catalysts tend to present higher ethylene selectivity as the reaction temperature increases.

The fabrication of qualified catalysts is a key issue to implement gas-phase aerobic alcohol oxidation but necessarily requires understanding the structures of catalytic active sites and the supply of active oxygen species. Herein, we present one example of the Ag–CoO/Ti- powder catalyst for gas-phase benzyl alcohol aerobic oxidation. The first interesting observation is that the Ag–Co3O4 ensembles on the fresh catalyst could be transformed into Ag–CoO due to the presence of reductive benzyl alcohol. The preferred catalyst with 3 wt% Ag and 3 wt% CoO exhibits 93% benzyl alcohol conversion and 99% benzaldehyde selectivity at a weight hourly space velocity of 20 h−1 and a temperature of 240 °C. The structures of Ag–CoO ensembles and oxygen species supply were probed and identified by electron microscopy and other spectroscopy techniques in combination with temperature-programmed thermal analyses, pulse experiments, and kinetic studies. In nature, the oxygen species is generated at the Ag–CoO interfacial sites in the form of atomic oxygen with appropriate chemisorption strength on these sites to achieve a high oxidation activity of benzyl alcohol. Moreover, the Co3O4 ↔ CoO cycle is promoted by Ag at low temperature such as 240 °C to endow the Ag–CoO ensembles with excellent catalytic performance.

Methyl glycolate (MG) is a versatile platform molecule to produce numerous important chemicals and materials, especially new-generation biocompatible and biodegradable poly(glycolic acid). In principle, it can be massively produced from syngas (CO + H2) via gas-phase hydrogenation of CO-derived dimethyl oxalate (DMO), but the groundbreaking catalyst represents a grand challenge. Here, we report the discovery of a Ni-foam-structured nanoporous Ni3P catalyst, evolutionarily transformed from a Ni2P/Ni-foam engineered from nano- to macro-scale, being capable of nearly fully converting DMO into MG at >95% selectivity and stable for at least 1000 h without any sign of deactivation. As revealed by kinetic experiments and theoretical calculations, in comparison with Ni2P, Ni3P achieves a higher surface electron density that is favorable for MG adsorption in a molecular manner rather than in a dissociative manner and has much higher activation energy for MG hydrogenation to ethylene glycol (EG), thereby markedly suppressing its overhydrogenation to EG.

Two novel kinds of low migration photoinitiators BRA and TXRA based on benzophenone (BP) and thioxanthone (ITX) were synthesized and used as Type II polymerizable photoinitiators. The structures were confirmed by proton nuclear magnetic resonance (1H NMR), carbon nuclear magnetic resonance (13C NMR), FT-IR and high resolution MS. The spectral properties were studied by Ultraviolet–Visible (UV–vis) spectroscopy. The photo-initiating activity of the initiators was evaluated by real-time RT-IR in the presence of a hydrogen donor such as triethylamine. The results show that they exhibited almost similar initiating activity as the reference BP or ITX, while exhibiting more low migration than the non-functionalized BP or ITX. These results suggest that BRA or TXPA is an efficient photoinitiator for reducing migration in photo-curing system.

Thin-felt microfibrous-structured Pd-Co-MnOx/Al2O3/Al-fiber catalysts (named Pd-Co-MnOx-Al) with low Pd-loading engineered from micro- to macro-scale are developed for the high-throughput catalytic decomposition of high level gaseous ozone (O3) under humid conditions. The catalysts are obtained by highly dispersing Pd-Co-Mn active components onto the γ-Al2O3 nanosheets endogenously grown on the thin-felt microfibrous structure consisting of 10 vol% 60 μm-Al-fiber and 90 vol% voidage, using impregnation method. This approach effectively and efficiently couples the unique form factor, thin-sheet feature, and high permeability with the high activity, markedly improved stability, and enhanced moisture resistance. The most promising 0.1Pd-Co-MnOx-Al (0.1 wt% Pd, 0.36 Co/Mn molar ratio, Co2O3 + MnO2 loading of 5 wt%) catalyst remains full O3 conversion for at least 4 h at 25 °C for a feed gas containing 1500 ± 45 ppm O3 even at a high relative humidity (RH) of 70%, using a high gas hourly space velocity of 48,000 mL gcat.–1 h–1; the full O3 conversion quickly slides to a flat of ~96% during 4 h testing at 90% RH whereas it is retrievable immediately after switching the feed gas to a dry one. The remarkable improvement of activity, stability and moisture resistance by Pd-doping of Co-MnOx-Al is, in nature, due to the highly improved and stabilized low-valent-Mn related oxygen vacancies (i.e., active sites) and markedly weakened H2O adsorption on the catalyst surface, which are verified by XRD, H2-TPR, O2-TPD, H2O-TPD and XPS measurements.

A high-performance, low Pd-loading and highly thermal conductive catalyst is developed by carburizing a thin-felt Pd/AlOOH/Al-fiber (0.25 wt% Pd) using ethylene. Carbon dissolving into the subsurface of Pd nanoparticles to form surface PdCx species (i.e., Pd@PdCx) leads to at least 2-fold improvement of the intrinsic activity (expressed by turnover frequency, TOF) for the CO oxidative coupling to dimethyl Oxalate, in nature, remarkably promoting the generation of key reaction intermediate of COCOOCH3* (*, a surface site).

A carbon-decorated Pd@C/ns-AlOOH/Al-fiber catalyst (0.24 wt% Pd) is engineered from nano- to macro-scales, which is promising for the vapor-phase synthesis of dimethyl carbonate (DMC) from methyl nitrite (MN) and CO. A high MN conversion of 99.9% with MN-based DMC selectivity of 39.1% and 70.6% CO conversion with CO-based DMC selectivity of 39.6% can be obtained at 220 °C for a feed of MN/CO/N2 (10/7/83) at a high gas hourly space velocity of 25,000 L kg−1 h−1. Moreover, the carbon decoration shows ability to improve the formation of electron-deficient Pd species, which is paramount for the enhanced selectivity to DMC.

A hollow-B-ZSM-5/SS-fiber catalyst is developed through alkali leaching of the full-silica core of the silicalite-1@B-ZSM-5 in situ structured onto a thin-felt stainless-steel fiber (20 μm SS-fiber), which is synthesized by a seed-assisted dry-gel vapor-phase transport method. As-obtained catalyst shows marked improvement in the mesoporosity-dependent diffusion (by o-xylene diffusion measurement). Boron incorporation is essential for preventing the framework dealumination during alkali leaching treatment due to the increased framework negative charges. The hollow-B-ZSM-5/SS-fiber catalyst shows remarkable stability improvement in the methanol-to-propylene (MTP) reaction because of the enhanced diffusion of the nano-hollow-structure and the boron-incorporation stabilized framework aluminum. A boron-free hollow-ZSM-5/SS-fiber is also obtainable with the textural properties comparable to the hollow-B-ZSM-5/SS-fiber but shows undesired degeneration of the tetra-coordinated aluminum. The preferential generation of coke in the micropores of the hollow-ZSM-5/SS-fiber causes a rapid deactivation even compared to the parent silicalite-1@ZSM-5/SS-fiber, due to the existence of extra-framework aluminum.

Corrosion protection using cold spraying is a promising method to address the shortcomings associated with classical techniques for protecting magnesium alloys from corrosion. In this study, SiCp/Al 5056 composite coatings were prepared on a magnesium substrate using cold spraying. The effects on the microstructure and corrosion properties after adding SiC were analysed. To evaluate the durability of the cold-sprayed Al-based coatings on Mg, galvanic corrosion, immersion and thermal cycling tests were conducted. The results show that cold-sprayed aluminium coatings serve as a reliable cathode for magnesium substrates. The addition of SiC particles increases the galvanic potential and decreases the galvanic reduction current of the coating/substrate couple. The SiCp/Al 5056 composite coatings show better corrosion resistance than that of the Al 5056 coating in extended immersion tests due to the densification of the coating under the peening effect of hard particles. Moreover, SiC particles with an average size of 15.6 &micro, m show more improvement than with SiC particles having an average size of 72.8 &micro, m. The cold-sprayed SiCp/Al 5056 composite coating also presents excellent properties in the thermal cycling tests. After applying failure mode parameters in the thermal cycling tests, the composite coating demonstrates good adhesion as cracking was located in the Mg substrate and not at the interface.

The seismotectonically induced changes in groundwater radon (Rn) are considered to be strong imputes for the surveillance of imminent major earthquakes. Groundwater facilitates the migration of soil gases as a result of tectonic stresses. In this regard, a radon time series is statistically analysed to identify the radon anomalies possibly induced by Wenchuan earthquake. The statistical analysis mainly involves the deterministic analysis of the Rn data and residual Rn analysis using a criterion x¯±2σ of anomaly selection having a confidence interval of 95%. The deterministic analysis reveals that the Rn time series follows a persistent trend 0.5≤H≤1 which confirms the absence of a chaotic regime. On the other hand, the residual Rn shows a notable upsurge straddling the time of the Wenchuan earthquake in the form of pre- and post earthquake changes at monitoring stations having RE/RD≤0.3. The residual Rn level passes the anomaly selection criterion x¯±2σ and is declared as a tectonically induced Rn anomaly. Contrary to this, the response of distant monitoring stations (RE/RD>0.3) to this particular earthquake further validates the link between Rn and earthquake activity. In a nutshell, the present study highlights the potential implications of earthquake-induced radon anomalies for earthquake prediction research.

Catalytic distillation (CD) has received inviting interests due to the green chemical process with a unique integration of catalytic reaction and distillative separation. This approach opens a promising way towards one-step cyclohexyl acetate production and cyclohexene-cyclohexane separation via esterification of cyclohexene (cyclohexene-cyclohexane mixture as feed) with acetic acid in a CD column, which can overcome many of the drawbacks encountered in the conventional reaction/separation processes. We present a microfibrous-structured Nafion-SiO2/SS-fiber solid acid catalyst as CD packings and demonstrate its high efficiency and effectiveness for synthesizing cyclohexyl acetate and separating cyclohexene/cyclohexane mixture in one-step. The Nafion-SiO2/SS-fiber catalytic packings achieved as-expected catalytic properties with respect to stability, adequate acidic sites and high mass/heat transfer, and therefore worked efficiently and effectively in the titled CD system. The operation parameters, including reboiler duty, molar ratio of acetic acid to cyclohexene, reflux ratio, and weight hourly space velocity (WHSV), were optimized with the aid of the factorial design based on response surface methodology (RSM). High actual yield of cyclohexyl acetate (78.1%) and high recovery of cyclohexane (93.0%) with 94.3% of cyclohexane purity were achievable, while such microfibrous-structured Nafion catalyst was stable for at least 200 h consecutive batch runs.

A series of Ni5Ga3/m-SiO2/Al2O3/Al-fiber (m = 0, 0.5, 1.0, 3.0 and 5.0 wt%) catalysts have been developed for CO2 hydrogenation to methanol at ambient pressure. Microfibrous-structured SiO2/Al2O3/Al-fiber supports are obtained though endogenous growth of free-standing boehmite (AlOOH) nanosheets onto a three-dimensional (3D) network of 60 μm-Al-fiber thin felt with the aid of steam-only hydrothermal oxidation reaction between Al metal and H2O (2 Al + 4H2O → 2 AlOOH + 3H2), followed by calcination and SiO2-modification using silica sol. The bimetallic Ni5Ga3 nanoparticles are then placed onto the pore surface of as-obtained SiO2/Al2O3/Al-fiber support by co-impregnation method using Ni and Ga nitrates as precursors followed by reduction in H2 at 630 °C. The promising Ni5Ga3/1-SiO2/Al2O3/Al-fiber catalyst is capable of converting 2.3% CO2 into CH3OH with a high selectivity of 86.7% as well as 10.3%/3.0% selectivities to CO/CH4 at 210 °C, for a feed of CO2/H2/N2 (2/6/1, molar ratio). Such microfibrous-structured catalyst design combines the promising catalytic performance of Ni5Ga3 with the enhanced heat transfer and high permeability of the Al2O3/Al-fiber support. The effect of SiO2 loading on the formation of Ni5Ga3 alloy nanoparticles is also discussed.

A promising thin-felt stainless-steel-fiber (SS-fiber) structured hollow-ZSM-5/SS-fiber catalyst is developed through alkali leaching of the full-silica core from the silicalite-1@ZSM-5/SS-fiber. A silicalite-1 seeded dry-gel/SS-fiber is obtained by dip-coating technique and is then transformed into the silicalite-1@ZSM-5/SS-fiber (overall SiO 2 /Al 2 O 3 molar ratio of 93) via seed-assisted dry gel conversion method. Such catalyst shows marked enhancement of mesoporosity development because of the abundant hollow structures left behind after the silicalite-1 core removal by alkali treatment in a mild Na 2 CO 3 media. The effect of alkali-treated time length on catalyst structure, textural and acidic properties as well as methanol-to-propylene (MTP) performance is systematically investigated. As-obtained catalyst, with well-maintained Bronsted acid sites after alkali treatment, shows hollow-structure-dependent stability improvement in the MTP and n-hexane cracking processes due to markedly enhanced diffusion.

A series of thin-felt SS-fiber@HZSM-5 catalysts are fabricated via the seed-assisted vapor-phase transport (VPT) method. The crystal size and mesoporosity of zeolite shell are controllably tuned toward enhanced diffusion by increasing the silicalite-1 seeding gel (SG) amount used. The microstructured catalyst obtained with a high SG amount of 50% contains a smaller crystal size of ∼70 nm and higher mesopore volume of 0.21 cm3 gzeolite−1, which markedly prolonged single-run lifetime with a remarkable decrease in the coking rate in the MTP process. The adverse effect of non-uniform aluminum in the zeolite shell on the MTP stability is revealed. The use of aluminum-containing SG to replace the pure-silica one makes the acid sites of as-obtained ZSM-5 mounted on SS-fiber distributed homogeneously thereby leading to a marked suppression of hydrogen transfer, and as a result, the catalyst single-run lifetime is further increased by ∼40%. This promising SS-fiber@HZSM-5 catalyst is stable for at least 1600 h (>94% conv.) with a high propylene selectivity of ∼36% at 450 °C using a WHSV of 1 h−1 for a feed of MeOH/H2O molar ratio of 1:1, by taking advantage of improved diffusion from mesoporosity development and uniform aluminum distribution as well as our distinctive microfibrous-engineered design.

Gold nanoparticles supported on Fe2O3 are a promising type of catalyst for CO oxidation. One challenge for their application in the real world is developing novel monolithic catalytic packings to meet the fundamental criteria (for example, high catalyst utilization efficiency and low pressure drop) needed for such high-throughput reaction process. Herein, a highly active and efficient thin-felt microfibrous-structured Au-α-Fe2O3/ns-γ-Al2O3/Al-fiber catalyst with unique form factor and high permeability is fabricated for the low-temperature CO oxidation. Initially, thin-felt Al-fiber felt (60 μm diameter; 85 vol% voidage) undergoes a steam-only oxidation and calcination to create a 0.7 μm mesoporous layer of γ-Al2O3 nanosheets (ns-γ-Al2O3) along with the Al-fiber. Subsequently, α-Fe2O3 is hydrothermally grown onto the ns-γ-Al2O3 layer followed by Au nanoparticle deposition via urea-assistant deposition-precipitation method. As-resulted microfibrous-structured Au-α-Fe2O3/ns-γ-Al2O3/Al-fiber catalysts effectively and efficiently couple the low-temperature activity and improved water vapor tolerance with enhanced catalyst accessibility and high permeability. The promising microfibrous-structured catalyst with only 0.14 wt% Au and 1.4 wt% α-Fe2O3 is capable of fully or 40% oxidizing CO into CO2 at 25 °C or 0 °C for a feed gas of 2 vol% CO and 0.3 vol% water vapor in air at a high linear velocity of 0.7 cm s−1, using a high gas hourly space velocity of 25,200 mL g−1 cat h−1. Moreover, the microfibrous-structured catalyst performs robustly for at least 232 h under the changeable temperature conditions. Interestingly, 3D hierarchical porous flake structure of α-Fe2O3 nano-sheets is detected other than the irregular micron-sized particles, leading to a 3-fold increase in the intrinsic activity (TOF of 0.46 s-1 for the Au-α-Fe2O3/ns-γ-Al2O3/Al-fiber vs. 0.11 s−1 for the Au-α-Fe2O3 powder at 25 °C).

A Nb2O5–NiO/Ni-foam catalyst engineered from nano- to macro-scale is developed by hydrothermal growth of NiC2O4 onto a Ni-foam and subsequent (niobium ammonium oxalate)-modification and calcination, which is highly active/selective and stable for the oxidative dehydrogenation of ethane to ethylene. External and partial coverage of the NiC2O4-derived NiO nanorods with Nb2O5 lumps, coupled with a foam-structure enhanced heat transfer, is paramount for high-efficiency ethylene production.

From macro- to nano-engineering of a promising CeO2-ZrO2-doped NiO-Al2O3/Ni-foam catalyst has been demonstrated for the oxidative dehydrogenation of ethane to ethylene (ODE), through facial wet chemical etching of a Ni-foam followed post modification with CeO2 and ZrO2. The NiO-Al2O3/Ni-foam (denoted as NANF) achieved a high ethane conversion of 25.2% but with a very low ethylene selectivity of 43.1% at 450 °C. ZrO2-doping of the NANF led to a remarkable improvement in the ethylene selectivity but serious deterioration of activity while the CeO2-doping showed an opposite effect. Co-doping of the NANF using optimal amount of CeO2 and ZrO2 markedly promoted not only the activity but also the selectivity to ethylene. For example, over the 1CeO2-5ZrO2-NANF (CeO2:1 wt%, ZrO2:5 wt%) catalyst, a high ethane conversion of 40.3% was obtained with a 60.6% ethylene selectivity for a feed gas of C2H6/O2/N2 = 1/1/8 at 500 °C and a gas hourly space velocity of 18,000 cm3 g−1 h−1, corresponding to a high ethylene productivity of 510 gEthylene kgcat−1 h−1. In nature, co-doping with CeO2 and ZrO2 synergistically tamed the NiO for selective H-abstraction of the ethane molecules other than over oxidation of them.

A high-performance Ni-foam-structured nano-intermetallic InNi3C0.5 catalyst is developed for the gas-phase hydrogenation of dimethyl oxalate (DMO) to ethylene glycol (EG). The InNi3C0.5/Ni-foam catalyst is obtainable by hydrothermal growth of NiC2O4 onto the Ni-foam, impregnation with In2O3 precursor, subsequent calcination and carburization in a syngas. Despite DMO cascade hydrogenation to MG, then to EG, and finally to EtOH, such catalyst hydrogenates DMO dexterously until to EG with a high turnover frequency of 636 h−1, because the 3Ni-In and 3Ni-C sites on InNi3C0.5(1 1 1) effectively activate DMO but hinder EG over-hydrogenation to EtOH. Favorable reaction pathway on the InNi3C0.5(1 1 1) surface predicted theoretically is DMO* → CH3OCOCO* → CH3OCOCHO* → CH3OCOCHOH* → MG* → CH3OCHOCH2OH* → CHOCH2OH* → HOCHCH2OH* → EG*. Moreover, the neutral Ni-foam diminishes the formation of ethers and diols. This catalyst achieves full DMO conversion with 96–98% EG selectivity and is stable for at least 2500 h under industrial-relevant conditions, and can also hydrogenate a broad scope of carbonyl compounds to corresponding alcohols with high yields.

A promising Ni-MoOx bifunctional catalyst for halide-free methanol carbonylation is developed by H2-reduction of NiO-MoO3/SiO2 obtained via facile impregnation method. Catalyst performance is strongly dependent on the calcination/reduction temperature. Over the preferable NiMo-350-600/SiO2 catalyst obtained by calcining at 350 °C and subsequently reducing at 600 °C, a methanol conversion of 4.2 % and acetyls space-time yield of 1.37 mol kgcat−1 h−1 are achieved with 22.1 % selectivity to acetyls at 290 °C and 3 MPa. Co-existence of Ni0 and MoOx (especially MoO2) markedly decreases formation of dimethyl ether (DME) and reversely increases acetyls formation, in nature, due to the catalyst acidity modulation and the partial electron transfer from Ni0 to MoOx that tunes the CO adsorption strength on Ni0 sites. MoO3 and NiMoO4 are both favorable for formation of acetyls and DME whereas the latter mainly accounts for DME formation. MoNi4 alone favors methyl formate formation while together with MoO2 enhancing DME production.

A facile strategy is reported for engineering layered double hydroxides (LDHs)-derived nanocomposite catalysts from nano-to macro-scales in one step, via the Al 2 O 3 /water interface-assisted method to embed LDHs onto monolithic substrates (such as thin-felt microfibrous structure using 22 μm FeCrAl fibers or 20 μm stainless steel fibers and SiC foam) followed by calcination to transform LDHs to nanocomposites. Such approach achieves unique integration of tunability and homogeneous distribution of catalytic components, enhanced heat/mass-transfer, self-supported feature, and high permeability, thus exhibiting tremendous potential for application in harsh reactions. For example, the thin-felt NiO MgO Al 2 O 3 /FeCrAl-fiber catalyst derived from NiMgAl-LDHs/Al 2 O 3 /FeCrAl-fiber offers high activity and stability for the high throughput and exothermic catalytic oxy-methane reforming: 87–90% methane conversion and 91–93/90–92% H 2 /CO selectivities at 700 °C within 300 h testing, using a high gas hourly space velocity of 72 L g −1 h −1 .

Self-supported NiO-MOx-Al2O3 (M = Ce or Mg) nanocomposites mounted on a Ni-foam (110 PPI) as the monolithic structured catalyst have been developed for the high throughput catalytic partial oxidation of methane to syngas. The catalysts are obtainable by direct growth of NiAl layered double hydroxides nanosheets and subsequent impregnation with boehmite sol containing Al-Ce or Al-Mg nitrates. Such catalysts are highly active and selective with promising stability in the title reaction, for example, the NiO-CeO2-Al2O3/Ni-foam achieves a high methane conversion of 86.4% with 91.2%/89.0% selectivities to H2/CO and is stable for at least 100 h at 700 °C and a high gas hourly space velocity of 100 L g−1 h−1. Thanks to a feasible CeO2↔CeAlO3 chemical cycling that is able to promote the O2 activation to create an oxidative environment around Ni particles, carbon formation rate is dramatically suppressed by a factor of at least 5 compared to the base catalyst.

BACKGROUND Catalytic distillation (CD) has been received as an inviting green chemical process for numerous catalytic esterification reactions. Rendering novel structured CD packings is particularly desirable but remains challenging. RESULTS We present a microfibrous-structured HZSM-5 solid acid catalyst as CD packings and demonstrate its separation and esterification reaction efficiency for producing ethyl acetate from acetic acid and ethanol. The factorial design based on response surface methodology is employed for fast determination of optimum reaction conditions, which is working effectively and efficiently. Such structured catalyst packings are obtained by direct growth of zeolite onto the θ-ring analogues shaped from a microfibrous-structure consisting of 15 vol% 20 µm stainless-steel-fiber (SS-fiber) and 85 vol% voidage. CONCLUSION The SS-fiber@HZSM-5 packings provide a unique combination of instantaneous distillation and desired catalytic properties with respect to stability, adequate acidic sites and high mass/heat transfer, and therefore work efficiently and effectively. High total (95.9%) and actual (90.9%) yields of ethyl acetate with 89.8% purity are achievable while the high CD efficiency was well-preserved after at least 240 h over 30 consecutive batch runs.

Microfibrous-structured SS-fiber@beta composites are synthesized by coupling dip-coating method with a seed-assisted dry-gel conversion method. The beta crystals in zeolite shell are formed by growth on the surface of pre-added beta seeds and TEAOH-induced nucleus. One interesting point is that this approach is working highly effectively and efficiently even at high dry gel SiO 2 /Al 2 O 3 ratio of 200 (corresponding to 207 in the beta zeolite shell). Such SS-fiber@beta composites show great potentials for the heat/mass transfer limited reactions due to their hierarchical porosity, small crystals, controllable acidity as well as our distinctive microfibrous-structured design.

The Mn2O3-Na2WO4/SiO2 catalyst is the most promising one among the enormous catalysts for the oxidative coupling of methane (OCM) but only at above 800 °C. No doubt that lowering temperature of the OCM process is at the forefront of this catalysis field. A promising low-temperature active and selective TiO2-doped Mn2O3 Na2WO4/SiO2 catalyst, consisting of 6 wt% TiO2, 6 wt% Mn2O3, 10 wt% Na2WO4 and SiO2 in balance, is developed by solution combustion synthesis (SCS) method. This catalyst is capable of converting 20% CH4 with 70% selectivity to C2-C3 hydrocarbons even at 700 °C (catalyst bed temperature) and is stable for at least 250 h without deactivation sign, for a feed gas of 50% CH4 in air using a gas hourly space velocity of 8000 mL gcat.−1 h−1. In contrast, the non-TiO2-doped SCS catalyst is almost inactive at 700 °C whereas it can achieve reactivity (∼24% CH4 conversion and ∼74% C2-C3 selectivity) comparable to the TiO2-doped one at 800 °C. XRD and Raman results evidently reveal that the formation of MnTiO3 during the OCM process appears to be important for the low-temperature OCM activity improvement by TiO2-doping.

A foam-structured Ag-CuOx nanocomposite catalyst obtained by sequential galvanic-deposition of 0.4 wt% Ag and 28 wt% Cu onto a Ni-foam, is highly active, selective and stable for the gas-phase hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG). The best catalyst 0.4-Ag-28-CuOx/Ni-foam was capable of converting more than 96% DMO into MG with a high selectivity of more than 96% and was stable for at least 200 h at 210 °C and a WLHSVDMO of 0.25 h− 1 for a feed of 13 wt% DMO dissolved in MeOH. Silver is responsible to apportion the proportion of Cu+ and Cu0 to an appropriate scale of optimal potency for converting DMO-to-MG.

An FeCrAl-fiber-structured NiO-MgO-Al2O3 nanocomposite catalyst engineered from nano- to macro-scale in one-step is developed via thermally decomposing NiMgAl layered double hydroxides (LDHs) that can be grown onto the FeCrAl-fiber only through a γ-Al2O3/water interface-assisted method. By taking advantages of homogeneous component-distribution in the LDHs-derived NiO-MgO-Al2O3 nanocomposites and enhanced heat transfer, this promising catalyst delivers satisfying performance with enhanced coking/sintering resistance in the title reaction. At 800 °C and a gas hourly space velocity of 5000 mL g–1 h–1, CH4/CO2 conversion maintains almost constant at 91%/89% within the initial 90 h and then slides in a smooth downturn (to 80/85%) within another 180 h of reaction.

A high-performance SiC-foam-structured nanocomposite catalyst of CoO@Cu2 O (i.e., 50-100 nm CoO partially covered with ca. 10 nm Cu2 O) was engineered from nano- to macro-scales in one step for the high-throughput gas-phase aerobic oxidation of bioethanol to acetaldehyde. This special CoO@Cu2 O nanostructure shows much higher activity/selectivity than other binary metal-oxide assemblies such as CuOx &CoO nano-mixtures or inverse Cu2 O@CoO nanostructures. The catalyst was facilely but exclusively obtainable by in situ reaction-induced transformation of the respective metal nitrates supported on SiC-foam into the CoO@Cu2 O nanostructure in the reaction stream. It achieved 95 % conversion with 98 % selectivity under mild conditions and was stable for at least 150 h for a feed of 20 vol % ethanol (much higher than in the literature: 1-6 vol %) at a high EtOH weight hourly space velocity of 8.5 h-1 . Abundant Cu2 O-CoO interfaces and high stability of the CoO@Cu2 O nanostructure were responsible for the high activity/selectivity and promising stability in this reaction.

Free-standing stainless-steel (SS)-fiber@meso-HZSM-5 core–shell catalysts engineered from micro- to macro-scale were highly efficiently synthesized via cost-effective steam-assisted crystallization (SAC) method. Impact of synthesis conditions on their morphology and textural/acidic properties was investigated by means of XRD, SEM, TEM, solid-state NMR, NH3-TPD, Py-IR and N2 physisorption. Single-run lifetime of such structured catalysts for MTP process was strongly dependent on their preparation conditions but slightly the product distribution. A volcano-like relationship for lifetime was observed against the SAC time, which was correlated well with the crystallization-time-dependent crystallinity, mesoporosity and crystal size. The promising SS-fiber@meso-HZSM-5 was the one obtained after the SAC for 12 h, which delivered a prolonged single-run lifetime of 620 h with a high propylene selectivity of ∼42% at 450 °C using a methanol weight hourly space velocity (WHSV) of 1 h–1, as the result of high crystal...

A thin-felt, microfibrous-structured Ni@SiO2/Al2O3/FeCrAl-fiber catalyst was fabricated by one-step, top-down macro–micro–nano organization with the aid of cross-linking molecules followed by a calcination treatment. This catalyst is active, selective and stable for the strongly endothermic dry reforming of methane (DRM), as the result of its enhanced resistance to coke and Ni sintering arising from its core–shell-like nanostructure. Notably, no sign of catalyst deactivation is observed, with almost no carbon deposition even after 500 h testing at 800 °C and a gas hourly space velocity of 5000 mL g−1 h−1.

Ni-foam-structured CeO 2 -NiO-Al 2 O 3 catalysts to be used for oxidative dehydrogenation of ethane to ethylene (ODE) have been developed, via chemically etching a Ni-foam followed by CeO 2 modification. The CeO 2 -NiO-Al 2 O 3 /Ni-foam catalysts are highly active and selective with promising stability. With the increase in CeO 2 loading up to 10 wt%, ethane conversion is increased monotonously while ethylene selectivity shows volcano-shaped evolution and reaches its maxima at 7 wt% CeO 2 loading. A high ethylene productivity of 425 g Ethylene kg cat − 1 h − 1 is achieved for a feed gas of C 2 H 6 /O 2 /N 2 = 1/1/8 at 450 °C and a gas hourly space velocity of 18,000 cm 3 g − 1 h − 1 . Promotion effect of CeO 2 additive is also discussed.

The catalytic oxy-methane reforming (COMR) is an effective and effcient route to produce syngas, but the commonly-used Ni catalysts suffer from coke deposition, Ni-sintering and heat transfer limitation. A Ni-foam-structured NiO-MgO-Al2O3 nanocomposite catalyst was developed via thermal decomposition of NiMgAl layered double hydroxides (LDHs) in situ hydrothermally grown onto the Ni-foam. Originated from the lattice orientation effect and topotactic decomposition of LDHs precursor, NiO, MgO and Al2O3 are highly distributed in the nanocomposites, and thus this catalyst delivered enhanced coke-/sintering-resistance. At 700 oC and a gas hourly space velocity of 100 L g-1 h-1, 86.5% methane conversion and 91.8%/88.0% selectivities to H2/CO could be achieved with a stability for at least 200 h. We anticipate that our approach opens a new opportunity for new-generate structured catalytic reactor for COMR process even other high-throughput and/or exothermic reaction processes.

Pd-catalyzed CO coupling to dimethyl oxalate (DMO) process has been commercialized but its reaction mechanism is still open for debate between COCOOCH3∗ and COOCH3∗ (∗, a surface site). In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) studies were performed to clarify such controversy on a high-performance Al-fiber@ns-AlOOH@Pd catalyst. Intermediate species consisting of stretching vibrations of CO and CO, and rocking vibration of CH3 was indeed captured, which could be assigned to either COCOOCH3∗ or COOCH3∗. To make discrimination between COCOOCH3∗ and COOCH3∗, methyl oxalyl chloride (CH3OCOCOCl) and methyl chloroformate (CH3OCOCl) were employed to form COCOOCH3∗ and COOCH3∗ species on the catalyst surface for DRIFTS analyses. Interestingly, the characteristic bands of the as-observed intermediate species in the real reaction matched the obtained COCOOCH3∗ species from dissociative adsorption of CH3OCOCOCl. A double carbonylation reaction pathway was thus confirmed for the CO coupling to DMO, i.e., consecutive insertion of two CO molecules into OCH3∗ to form COCOOCH3∗ followed by combining OCH3∗ to yield DMO (CH3OCOCOOCH3).

The Ni/SAPO-11 bifunctional catalyst for hydroisomerization of n-hexane was prepared via a novel synthesis method. It involved grinding of nickel source with amorphous precursors used for SAPO-11 followed by crystallization at 473 K for 24 h, thus avoiding the use of extra solvents in the synthesis. The highly dispersed nickel species and acid sites in the Ni/SAPO-11 bifunctional catalyst were instantaneously formed. The Ni/SAPO-11 catalyst contains framework nickel, nickel monoxide (NiO) and nickel aluminate spinel. The nickel monoxide with a size of 2–4 nm provides (de)hydrogenation function after reduction, while the framework nickel supplies more acid sites leading to an enhanced isomerization activity. The Ni/SAPO-11 catalyst shows a great synergetic effect between the metallic nickel and acid sites with a high metal-to-acid sites ratio (CNi/CA) and close proximity. A single metallic nickel site is able to balance ca. 5 acid sites (CNi/CA ≈ 0.19) over the Ni/SAPO-11 catalyst in n-hexane hydroisomerization. The high dispersion of nickel over the catalyst provides relatively excessive metal sites (CNi/CA > 0.19), leaving the rate limiting reaction to occur on the acid sites. The Ni/SAPO-11 catalyst exhibits comparable n-hexane conversion (71.2%) and iso-hexane yield (66.7%) to the classical Pt/SAPO-11 catalyst. With enhancing acidity, the Ni/SAPO-11 catalyst exhibits one of the highest iso-hexane yields reported in the n-hexane hydroisomerization, which render the new material as a promising candidate for the hydroisomerization catalysts.

Deep dry screening is the key unit in mineral processing. A vibrating flip-flow screen (VFFS) with elastic sieve mats has been widely used for screening fine-grained minerals due to its good performance. The stability of the VFFŚs dynamic response largely affects its screening efficiency and processing capacity, however, it has rarely been investigated in detail. In this paper, aiming at reducing the effect of loading-material for dynamic system through properly operated parameters, stability regions were defined, and for the given working conditions, using performance criteria to evaluate the vibration stability. This was done by theoretical modeling and experimental analysis for the VFFS system. The VFFS can operate in different regions by regulating the shear spring characteristics and the eccentric mass moment. The dynamic response curves were measured and analyzed under different operating conditions; and then, material-loading experiments were carried out to verify the stability of VFFS; furthermore, the method of multistage sampling and multilayer was used to analyze the screening performance of material under three conditions. Results indicated that loading material on VFFS affected its vibration stability and therefore the screening performance. The dynamic response of VFFS was more stable in the near anti-resonance region (a certain distance to the left of anti-resonance frequency) than the other two operating conditions, thus, was not obviously affected by loading material. Screening efficiency for 3 mm material was up to 89.05% with a corresponding total misplaced material of 7.96%.

A Ni-foam-structured PdNi nanoalloy catalyst engineered from nano- to macro-scales has been successfully fabricated for the catalytic deoxygenation of coalbed methane (CBM). The catalyst was obtainable by embedment of Pd nanoparticles onto Ni-foam substrate via a galvanic exchange reaction method and subsequent in situ activation in the reaction, which was active at low temperature, selective (no CO formation), and oscillation free in this CH4-rich catalytic combustion process. Special Pd@NiO (Pd nanoparticles partially wrapped by tiny NiO fragments) ensembles were formed in the galvanic deposition stage and could merely be transformed into PdNi nanoalloys in the real reaction stream at elevated temperatures (e.g., 450 °C or higher). Density functional theory (DFT) calculations were carried out to reveal the role of Ni decoration at Pd in PdNi nanoalloy catalyst for the CBM deoxygenation. By nature, the Pd–Ni alloying modified the electronic structure of surface Pd and led to a decrease in the O adsorptio...

A high-performance PdNi(alloy)/Ni-foam catalyst to be used for coalbed methane (CBM) deoxygenation via catalytic combustion was developed with the aid of galvanic deposition of Pd nanoparticles onto the monolithic Ni-foam followed by in-situ reaction-induced Pd-Ni alloying. The investigations concerning the preparation/reaction conditions and heat/mass transfer indicated that such PdNi(alloy)/Ni-foam catalyst provided a unique combination of high low-temperature activity/selectivity, oscillation-free, high permeability and enhanced heat transfer. As an example, the catalyst with a low Pd-loading of 1 wt% could deliver a complete O 2 conversion for a simulated feed of CH 4 /O 2 /N 2 (40/3/57, vol%) at 350 °C with a high gas hourly space velocity of 12,000 mL g cat. −1 h −1 , and particularly, this catalyst was stable for at least 500 h without deactivation and reaction oscillation. In-situ reaction-induced Pd-Ni alloying was clearly revealed and by nature was responsible for the low-temperature activity (expressed by turnover frequency) promotion and oscillation suppression. The underlying mechanism for CBM deoxygenation over the PdNi(alloy)/Ni-foam catalyst is proposed to be a Langmuir-Hinshelwood type.

Thin-sheet microfibrous-structured Al-fiber@ns-AlOOH@Pd catalysts with low Pd-loading engineered from micro- to macro-scale are developed for the gas-phase CO coupling to dimethyl oxalate, providing unique combination of high activity/selectivity and good stability with high permeability and high thermal conductivity. The support of Al-fiber@ns-AlOOH is initially prepared via endogenous growth of boehmite nanosheets (ns-AlOOH) on 3D network of 60-μm Al-fiber. The palladium is then placed onto the surface of the ns-AlOOH rooted on the Al-fiber via incipient wetness impregnation method with a toluene solution of palladium acetate. As an example, the catalyst with a low Pd-loading of 0.25 wt% delivers ∼66% CO conversion and ∼94% DMO selectivity for a feed of CH 3 ONO/CO/N 2 (10/14/76, vol%) with a gas hourly space velocity of 3000 L kg −1 h −1 , and particularly, is stable for at least 200 h without deactivation. Our Al-fiber@ns-AlOOH@Pd catalyst demonstrates two times higher intrinsic activity (expressed by turnover frequency) compared to a traditional Pd/α-Al 2 O 3 . The existence of Pd-hydroxyl synergistic interaction is paramount to the enhanced catalytic performance for the CO coupling reaction, by nature, as the result of hydroxyl-promoted adsorption of bridged CO on the Pd surface.

Free-standing NiO–MgO composite nanosheet catalysts to be used for catalytic oxy-methane reforming (COMR) have been developed by in-situ growing onto the Ni-foam struts under hydrothermal condition followed by calcination treatment. Among them, the NiO–MgO/Ni-foam consisting of 1.0% MgO, 18.7% NiO and nickel-foam-strut balance is the best structured catalyst engineered from nano- to macro-scale, being capable of converting 82.9% CH4 into syngas at selectivity of 94.7% to H2 and of 89.9% to CO for a feed of CH4/O2=2/1 (vol/vol), at 700 °C and a high gas hourly space velocity of 100 L g−1 h−1. Nevertheless, improvement of their carbon resistance and textural stability is particularly desirable.

For the methanol-to-propylene process, a lumped kinetic model was developed on the basis of dual-cycle reaction mechanism, which attempted to reflect the main reaction paths with a combination to show the evolution of mole fraction of individual light olefins ( C 2 , C 3 and C 4 ) with space time. The experiments were performed in a continuous flow fixed-bed reactor at 0.1 MPa as well as varied reaction temperature from 400 to 480 °C and space time from 0.3 to 32.0 gcatalyst h mol−1, and the experimental data obtained on the structured SS-fiber@HZSM-5 and powdered HZSM-5 catalysts were fitted by MATLAB software based on the established model. The fitted results show that the lumped kinetic model well describes the product distribution and is identified to be suitable by model identification. Compared to the powdered HZSM-5, the SS-fiber@HZSM-5 shows higher diffusion efficiency and narrower residence time distribution, not only promoting the propylene formation but also improving the utilization efficiency of the structured HZSM-5.

Structured Pd–Au–CuOx/Cu-fiber obtainable by a galvanic co-deposition method is post-modified by La2O3 and consequently shows promising low-temperature activity and stability for the titled reaction, due to the in situ formation of a La2O3–PdAu(alloy)–Cu nanocomposite in the reaction thereby leading to enhanced ability for H2 activation and H-spillover associated with the La2O3-assisted activation of CO and C–O groups of dimethyl oxalate.

Promising microfibrous-structured Al-fiber@ns-Al2O3@Fe–Mn–K catalysts are developed for the mass/heat-transfer limited Fischer–Tropsch synthesis of light olefins. The Al-fiber@ns-Al2O3 core–shell composites, engineered on the nano- to macro-scale, are first prepared by endogenously growing thin shell (∼0.5 μm) nanosheet γ-Al2O3 (ns-Al2O3) onto the 3-dimentional microfibrous-structured network consisting of 10 vol% 60 μm Al-fiber and 90 vol% voidage. After modification by K through an impregnation method, the Al-fiber@ns-Al2O3 composites are functionalized with nano-structured Fe and Mn active components via a surface impregnation combustion method. The effect of combustion atmospheres (air, N2, and N2 followed by air (N2–air)) on the catalyst performance is investigated. The as-burnt catalyst obtained under air delivers the highest iron time yield of 206.0 μmolCO gFe−1 s−1 at 89.6% CO conversion with 42.1%C selectivity to C2–C4 olefins (350 °C, 4.0 MPa, 10 000 mL (g−1 h−1)), while the other two as-burnt catalysts under N2 and N2–air yield relatively low CO conversions of 58–67%. Combustion under air is helpful to form 6 nm Fe–Mn–K oxide particles with better reducibility and carbonization properties thereby leading to high performance. In contrast, under either N2 or N2–air atmosphere, smaller oxide particles (3–4 nm) are formed but suffer from deteriorated reducibility and carbonization properties due to the strong support–metal interaction. Such as-burnt catalysts obtained under air also demonstrate promising stability.

A self-supported SS-fiber@meso-HZSM-5 core–shell catalyst was essentially designed and engineered from micro- to macro-scale by caramel-assistant hydrothermal synthesis. The significant role of caramel during the crystallization process was revealed in detail. Caramel not only created the mesoporosity in the ZSM-5 crystals, but also released acid under hydrothermal synthesis conditions which lowered the zeolite crystallinity. By taking advantage of the mesopore development in a hierarchical micro–meso–macropore structure with favourably-tuned acidic properties, such a catalyst provided a dramatically prolonged lifetime of 845 h (>90% conv.) with high propylene selectivity (e.g., 48%) in the MTP reaction. The hierarchical pore structure development mainly increased the accommodation capacity of the zeolite shell for receiving formed coke thereby leading to a dramatically prolonged lifetime in the MTP reaction.

Production of substitute natural gas (SNG) by methanation of syngas generated from various carbon sources provides a promising route towards coal clean utilization and sustainable energy future. Monolithic Ni (or Cu, NiCu-alloy)-foam-structured Ni–Al2O3 catalysts were developed by a facile modified wet chemical etching method. The as-prepared catalysts were characterized by X-ray diffraction, scanning electron microscopy, inductively coupled plasma atomic emission spectrometry and H2-temperature programmed reduction. Among these catalysts, Ni–Al2O3/Ni-foam has the most surface active Ni atoms and exhibits the best catalytic methanation performance, achieving 99.9% CO conversion with 90.0% methane selectivity and being stable for at least 1000 h for a feed gas of H2/CO (3/1) at 330 °C and gas hourly space velocity (GHSV) of 5000 h−1. Effects of reaction temperature, reaction pressure and GHSV are also investigated on the catalytic performance of Ni–Al2O3/Ni-foam for CO methanation. Computational fluid dynamics calculation and experimental measurement consistently show that such monolithic Ni–Al2O3/Ni-foam can dramatically reduce the “hotspot” temperature due to its high thermal conductivity. Moreover, the feasibility of our Ni–Al2O3/Ni-foam catalyst for co-methanation of a simulated feed gas from coal gasification is studied as well as CO2 methanation in the presence of high CH4 concentration. We anticipate that our present work might stimulate commercial exploitation of the new-generation structured catalyst and reactor technology for the strongly exothermic syngas methanation toward energy-efficient process for SNG production.

Catalytic distillation (CD) offers a unique integration of distillation and catalysis to selectively separate products in situ while making a positive shift of chemical equilibrium and has therefore been well received as an inviting avenue to green chemical processing. Rendering novel structured catalytic packings is particularly desirable but remains challenging. Herein, we present a microfibrous-structured Nafion–SiO2/SS-fiber solid acid catalyst and demonstrate its separation and reaction efficiency as CD packings for esterification to produce ethyl acetate from acetic acid and ethanol. A thin-sheet microfibrous structure with 15 vol% 20 μm stainless steel fibers (SS-fiber) and 85 vol% void volume was shaped into θ-ring analogues. Nafion was then firmly locked into the SiO2 layer that was anchored onto the SS-fiber surface by a dip-coating method using self-crosslinking Nafion–SiO2 sol–gel prepared by Nafion-catalyzed hydrolysis of tetraethylorthosilicate (TEOS). Such micro-structured Nafion catalysts worked effectively and efficiently in the CD for esterification of acetic acid with ethanol as the result of a unique combination of high catalyst performance (stability, adequate acidic sites and high mass/heat transfer) and instantaneous distillation. For instance, high total (93.6%) and actual (91.6%) yields of ethyl acetate with 96.2% purity were achievable at a high space-time yield (4.3 g mmol−1 h−1) while the high CD efficiency was maintained for 40 h over 5 consecutive batch runs.

Thin-felt NiO-Al2O3/FeCrAl-fiber catalysts engineered from micro- to macro-scales are developed for the high-throughput catalytic oxy-methane reforming to syngas. Crystallization-driven self-assembly process is used to prepare an Al(OH)3/FeCrAl-fiber support (15 wt% Al(OH)3). NiO of ~ 3 wt% is then highly dispersed onto above support via incipient wetness impregnation method followed by a calcination treatment. Such catalyst achieves a high CH4 conversion of 88.6% with 90.7%/93.2% selectivity to H2/CO at 700 °C and a high gas hourly space velocity of 80 L g− 1 h− 1, and is stable for at least 30 h without carbon deposit but a slight sintering. In contrast, a reference catalyst of NiO/FeCrAl-fiber shows a fast deactivation within only 6 h.