Activation Of Reactant Molecules Research Articles

Preparation of Z-type black-TiO2/Bi2WO6 heterostructure with metallic Bi and oxygen vacancies for boosting the toluene photooxidation

Photocatalytic oxidation is considered to be the most energy-efficient, environment-friendly and effective strategy to degrade low fraction organic contaminants. Hence, a range of black-TiO2/Bi2WO6 (BTB) composites containing metallic Bi and oxygen vacancies (OVs) were designed with the assist of reducing atmospheres (NH3, N2 and H2). The BTB-N2 gave the maximal toluene oxidation efficiency of 92.4 % within 120 min under visible light, which was significantly higher than that of other BTB materials. A synergistic effect of Z-type heterostructure, surface plasmon resonance (SPR) effect of metallic Bi, along with OVs engineering contributed to the outstanding photooxidation performance of BTB-N2. The establishment of Z-type heterostructure facilitated the charge separation with maintaining original redox properties of both semiconductors. Additionally, the proper concentration of metallic Bi and OVs in BTB-N2 could also promote charge separation and transportation, as well as offer more active sites for the adsorption and activation of reactant molecules in the toluene oxidation process. The in-situ infrared measurements revealed that BTB-N2 promoted the benzene ring opening, leading to the swifter transfer of adsorbed toluene and intermediates in comparison to BTB-Air. This work presented a new perspective to design highly effective Z-type photocatalysts for environmental remediation.

Construction of metal-anchored and defect-rich N-doped lignite-char supported cobalt catalysts for pressurized dry reforming of methane

Dry reforming of methane (DRM) offers a promising path for greenhouse gas conversion, but industry usually relies on pressurization conditions, and the drawback of rapid carbon deposition leading to deactivation of conventional catalysts under pressurization has hindered its industrial development. In this study, a cost-effective N-doped Co-based DRM catalyst was developed by utilizing melamine to induce heteroatom doping defects on modified lignite to overcome the problem of deactivation due to rapid carbon deposition under pressurized conditions. The catalyst, Co/CN-40 (Impregnated with 40 wt% melamine), has the smallest metal particle size (3.13 nm), the largest specific surface area (376 m2/g), high defectivity (ID/IG ratio = 0.84), enhanced metal-support interactions and a relatively high pyridine N content (48%). The evaluation of DRM activity and stability at 780 °C and 0.5 MPa demonstrates that Co/CN-40 offers the highest catalytic efficiency. The highest conversion was quickly achieved by the catalyst during activity assessments, and maintain an efficient conversion with suppressed metal agglomeration over a 100-h stability test. These improvements are attributed to the increase in the number of defects which enhances electron transfer, improves metal anchoring and boosts the adsorption and activation of reactant molecules.

An electrochemical flow cell for operando XPS and NEXAFS investigation of solid–liquid interfaces

Suitable reaction cells are critical for operando near ambient pressure (NAP) soft x-ray photoelectron spectroscopy (XPS) and near-edge x-ray absorption fine structure (NEXAFS) studies. They enable tracking the chemical state and structural properties of catalytically active materials under realistic reaction conditions, and thus allow a better understanding of charge transfer at the liquid–solid interface, activation of reactant molecules, and surface intermediate species. In order to facilitate such studies, we have developed a top-side illuminated operando spectro-electrochemical flow cell for synchrotron-based NAP-XPS/-NEXAFS studies. Our modular design uses a non-metal (PEEK) body, and replaceable membranes which can be either of x-ray transparent silicon nitride (SiN x ) or of water permeable polymer membrane materials (e.g. NafionTM). The design allows rapid sample exchange and simultaneous measurements of total electron yield, Auger electron yield and fluorescence-yield. The developed system is highly modular and can be used in the laboratory or directly at the beamline for operando XPS/ x-ray absorption spectroscopy investigations of surfaces and interfaces. We present examples to demonstrate the capabilities of the flow cell. These include an operando NEXAFS study of the Cu-redox chemistry using a SiN x /Ti-Au/Cu working electrode assembly (WEA) and a NAP-XPS/-NEXAFS study of water adsorption on a NafionTM polymer membrane based WEA (NafionTM/C/IrO x catalyst). More importantly, the spectro-electrochemical flow cell is available for user community of B07 beamlines at Diamond Light Source.

Hierarchically Porous Carbonized Wood Decorated with MoNi4‐Embedded MoO2 Nanosheets: An Efficient Electrocatalyst for Water Splitting

AbstractDevelopment of low‐cost electrocatalysts for water splitting is crucial to economical hydrogen production. Here, a highly efficient electrocatalyst composed of MoNi4‐embedded amorphous MoO2 nanosheets grown on less‐tortuosity hierarchically porous carbonized wood (MoNi4/MoO2@CW) is reported. The generation of abundant MoNi4/MoO2 heterointerfaces and defects‐rich MoO2 significantly promote the adsorption and activation of reactant molecules on the MoNi4/MoO2@CW. The obtained MoNi4/MoO2@CW catalyst exhibits ultralow overpotentials of 22 and 205 mV for hydrogen evolution reaction and oxygen evolution reaction at a current density of 10 mA cm−2, respectively. The catalyst can be used for dual‐function electrodes and assembling two‐electrode electrolyzer illustrates 10 mA cm−2 at 1.47 V and superior durability over 24 h for overall water electrolysis. Moreover, it also possesses a high mass activity of 142 Ag−1 MoNi4 at 200 mV, surpassing the Pt/C catalyst (132 Ag−1). The outstanding performance of the MoNi4/MoO2@CW is attributed to the decrease in energy barrier for water dissociation, optimal adsorption/desorption of H/O‐intermediates, and fast mass transport through the porous structure, as confirmed by experimental results and density functional theory‐based calculations. The MoNi4/MoO2@CW electrocatalyst has excellent potential for practical water splitting.

Catalytic methane combustion at low temperatures over YSZ-supported metal oxides: Evidence for lattice oxygen participation via the use of C18O2

Catalytic methane combustion was carried out over YSZ, Pd/YSZ and Rh/YSZ between 200 and 700 °C. Despite similar light-off curves for Pd/YSZ and Rh/YSZ between 200 and 450 °C, isotopic exchange experiments using CD4 and 18O2 revealed different behaviour of both supported catalysts regarding the activation of reactant molecules. The use of C18O2 isotopic gas was shown to be more appropriate than 18O2 to evaluate the bulk oxygen mobility in YSZ at low temperatures. The exchange of gaseous CO2 with lattice YSZ oxygen atoms, which occurs via surface hydrogen carbonate intermediate species, allowed to demonstrate the contribution of bulk oxygen atoms of YSZ in Rh/YSZ at low temperatures.

Catalytic combustion of propane over Mg-modified Co1.5Mn1.5O4 spinel catalysts: Boosting C-H cleavage with Lewis acid and oxygen vacancies

Rational modulation of surface electronic structure can optimize the adsorption and activation of reactant molecules on the catalyst surface, which is crucial for catalytic elimination of hydrocarbons. Herein, a facile low-valence Mg doping strategy was applied to synthesize highly active and stable Co-Mn binary oxide (CMO) catalyst. Lewis acid sites and oxygen vacancies were purposefully introduced on CMO through the surface electron deficit caused by the substitution of doped Mg for host metals. For the CMO catalyst modified by appropriate amount of Mg (CMO-Mg0.05), the Co-Mn spinel with lattice expansion is significantly modified through substitution of Co or Mn ions with Mg2+, resulting in generation of abundant higher metal oxidation state species (Co3+, Mn4+) and oxygen vacancies. The best performance for catalytic propane combustion was achieved on CMO-Mg0.05 catalyst, with the T90 at 255 °C under high space velocity (60,000 ml g−1 h−1). Meanwhile, clear improvements on stability and water resistance were also achieved after the modification of Mg in CMO catalyst. Combined with C3H8-TPD, in-situ DRIFTS and various characterizations, it can be revealed that the synergistic effect of Lewis-acid sites and oxygen vacancies would remarkably promote the process of propane dissociative adsorption and mineralization. This work not only gives insight into the Mg dopants in boosting CH activation on CMO catalyst, but also provides a potential strategy for fabricating highly active hydrocarbon combustion catalysts.

Insight into the activation of CO2 and H2 on K2O-adsorbed Fe5C2(110) for olefins production: A density functional theory study

The activation of reactant molecules on catalyst surface plays critical roles in the catalytic reaction process. The activation of CO2 and H2 molecules on clean and K2O-adsorbed Fe5C2(110) were comparatively investigated via density functional theory (DFT) calculations to disclose the promoting effect of K2O on hydrogenation of CO2 to olefins. DFT calculations suggest that the adsorption of K2O helps to direct activation of CO2 to CO species, and then promote in-situ CC* coupling of CO with surface carbon of χ-Fe5C2. The Fe-H bond from H2 dissociation on K2O-adsorbed Fe5C2(110) can lower the activity of H species, by which helps to avoid the over-hydrogenation of olefins to saturated alkanes. This study partially reveals the promoting effect of K2O on the activation of reactant molecules on χ-Fe5C2 surface, which is helpful to design new catalysts for CO2 conversion to value-added chemicals.

Imidazole-Functionalized Porous Graphene Oxide Nanosheets Loaded with Palladium Nanoparticles for the Oxidative Amidation of Aldehydes

In this study, 1-(3-aminopropyl)imidazole-functionalized porous graphene oxide nanosheets (GONs) decorated with palladium nanoparticles (Pd NPs; size, ∼11 nm) have been developed. This has been accomplished via covalent immobilization of amine-terminated imidazolium moieties over GONs, which were further decorated with Pd NPs by employing chemical reduction method. To authenticate the successful preparation of a nanocatalyst (i.e., GO-Imd-Pd), numerous physicochemical characterization techniques, such as FT-IR, XRD, TEM, TGA, SEM, EDAX, XPS, CHN, ICP-MS, and BET surface area analysis, have been utilized. The synthesized hybrid nanomaterial could validate its supremacy as a highly efficacious and heterogeneous nanocatalyst for the oxidative amidation of aldehydes. The prepared hybrid nanomaterial could offer Lewis acidic sites, which could help in the activation of reactant molecules, thereby delivering a high yield of the product. The prepared hybrid nanomaterial could be effortlessly separated from the reaction mixture by simple centrifugation technique. Also, the prepared nanocatalyst showed magnificent recyclability up to six catalytic runs without any perceptible loss in its activity and showed no sign of disintegration.

Selective oxidation conversion of methanol/dimethyl ether.

As important platform compounds, methanol and dimethyl ether (DME) are vital bridges between the coal chemical, petrochemical and fine chemical industries. At present, the synthesis of methanol/DME has been industrialized, and the production capacity is much larger than the market demand. Therefore, the conversion of methanol/DME into more valuable chemicals is an important and significant topic. The synthesis of high value-added oxygenated chemicals and diesel oil additives from methanol/DME by an oxidation method has attracted substantial attention due to it being green and environmentally friendly and having good atom economy. In this feature article, we have summarized the recent advances in the synthesis of formaldehyde, methyl formate, dimethoxymethane, and polyoxymethylene dimethyl ethers, from the selective oxidation of methanol/DME, and further discussed the adsorption and activation of reactant molecules, selective cleavage of C-O, C-H or O-H bonds in methanol/DME molecules and the C-O chain growth in the target products. In the end, major challenges and future prospects are proposed from the viewpoint of catalyst design and application. It is expected that this feature article will provide theoretical guidance for the activation and cleavage of C-O, C-H, or O-H bonds in other small molecules of alcohol/ether as well as low-carbon alkanes, so as to synthesize high value-added chemicals.

Artificial frustrated Lewis pairs facilitating the electrochemical N2 and CO2 conversion to urea

Frustrated Lewis pairs (FLPs) containing sterically hindered Lewis acidic and basic sites can capture and react with N 2 and CO 2 , thus furnishing a new strategy for urea electrosynthesis. Herein, the rice-like InOOH nanoparticles coupled with the well-defined FLPs (i.e., In In-OH) were synthesized and exhibited a urea yield rate of 6.85 mmol h −1 g −1 and faradic efficiency of 20.97% at −0.4 V versus reversible hydrogen electrode. Systematic investigations reveal that the electron-deficient Lewis acidic In sites and electron-rich Lewis basic In-OH achieve the targeted chemisorption of the N 2 and CO 2 molecules by electronic interaction respectively. The bonding and antibonding orbitals of reactant molecules interact with the unoccupied orbitals of Lewis acid and nonbonding orbitals of Lewis base to generate the desired intermediates for urea synthesis in artificial FLPs. In addition, FLPs can further ensure the orbital-matched intermediates of ∗N=N∗ and CO proceed with the desirable C–N coupling reaction to produce ∗NCON∗ precursors. • A rich-like InOOH nanocrystal coupled with frustrated Lewis pairs is synthesized • The frustrated Lewis pairs enable the targeted adsorption of reactant molecules • The activation of reactant molecules was achieved by orbital interaction • The designed InOOH exhibits Faradaic efficiency of 20.97% at −0.4 V versus RHE Electrochemical activation of inert N 2 and CO 2 molecules through C–N coupling reaction under ambient conditions is a top-challenging reaction that is promising for sustainable development and decreases of CO 2 emission. Urea, as the final product of this C–N coupling reaction, is an ideal chemical for both N 2 and CO 2 fixation. However, the desired urea electrosynthesis process was limited by the weak adsorption and activation ability of inert gas molecules on the catalyst's surface and vicious parallel reduction reaction of CO 2 and N 2 . Inspired by the electronic structures of reactant molecules and the orbital components of ∗N=N∗ and ∗CO intermediates, this work precisely engineered frustrated Lewis pairs in InOOH nanocrystal, which achieves the active site integration and the effective electrocatalytic C–N bond coupling to synthesize urea. Urea electrosynthesis is essential for achieving the both N 2 and CO 2 fixation. Herein, a highly efficient InOOH nanocrystal coupled with frustrated Lewis pairs is rationally designed. The electron-deficient Lewis acidic In sites and electron-rich Lewis basic In-OH achieve the targeted chemisorption of the N 2 and CO 2 molecules by electronic interaction respectively. Besides, the activation of reactant molecules was achieved by orbital interaction. Thus, the InOOH catalysts exhibit high intrinsic activity toward the urea electrosynthesis.

Lead-free B-site bimetallic perovskite photocatalyst for efficient benzylic C–H bond activation

Although bismuth (Bi)-based halide perovskites have attracted profound attention in photocatalysis, the undesirable photophysical properties are not well modulated, and the effect of surface structure on adsorption and activation of reactant molecules is still unclear. Here, we report the structural design, via precise incorporation of antimony (Sb) atoms into the host lattice of Cs 3 Bi 2 Br 9 , of a series of B-site bimetallic perovskites (Cs 3 Sb x Bi 2-x Br 9 , 0 ≤ x ≤ 2) with tunable band structures. The incorporation of Sb dramatically enhances the separation and transfer of photogenerated charges and prolongs their lifetimes. Considering these advantages, Cs 3 SbBiBr 9 exhibits significantly enhanced photocatalytic activities in challenging benzylic C–H activation while maintaining a high selectivity of 96%. Theoretical calculations reveal that the introduction of Sb breaks the symmetry of the local structure and leads to asymmetric charge distribution that not only increases the adsorption capacity for methylbenzene but also reduces the energy barriers for C–H bond activation. • Lead-free B-site bimetallic perovskites with tunable band structures • Enhanced photogenerated charges separation and transportation for Cs 3 SbBiBr 9 • Improved adsorption and activation for C–H bond by local structure modulation Shi et al. propose a crystal structure design strategy to tune the electronic band structure and photogenerated carrier properties of lead-free halide perovskites. Furthermore, they reveal that the regulation of local structural symmetry could modulate the surface charge distribution and improve the adsorption and activation of C–H bond.

Modulating oxygen vacancies on bismuth-molybdate hierarchical hollow microspheres for photocatalytic selective alcohol oxidation with hydrogen peroxide production

Photocatalytic selective oxidation of alcohols into high value-added carbonyl compounds accompanied by producing hydrogen peroxide (H2O2) is undoubtedly a more efficient solar energy conversion strategy with high atom economy. Herein, we have developed an efficient photocatalyst of bismuth-molybdate (Bi2MoO6) hierarchical hollow microspheres with tunable surface oxygen vacancies (OVs) for promoting the photocatalytic selective alcohol oxidation with H2O2 production. The effect of surface OVs on the photocatalytic efficiency is studied systematically by comparing the performance of different photocatalysts. The benzaldehyde and H2O2 production rates over the OV-rich Bi2MoO6 photocatalyst reach up to 1310 and 67.2 μmol g−1 h−1, respectively, which are 2.3 and 4.0 times those generated from the OV-poor Bi2MoO6 hollow microspheres. The roles of various active radicals in the photocatalytic reaction are probed by a series of controlled experiments and in situ ESR measurements, revealing that both superoxide radical (•O2-) and carbon-centered radical are the key active intermediates. The introduction of surface OVs on Bi2MoO6 hollow microspheres accelerates the separation and transfer of photo-generated charge carriers as well as enhances the adsorption and activation of reactant molecules, thereby greatly promoting the photocatalytic selective oxidation of alcohols along with H2O2 production. This work not only demonstrates a facile strategy for the preparation of high-efficiency photocatalysts by simultaneous modulations of morphology and surface defects, but also offers insight into developing the dual-functional photocatalytic reactions for the full utilizations of photoinduced electrons and holes.

Amino-mediated anchoring of FAPbBr3 perovskite quantum dots on silica spheres for efficient visible light photocatalytic NO removal

The superior optical properties and adjustable bandgap allows for hybrid halide perovskite quantum dots to be promising photocatalytic materials, but the serious radiative recombination and instability inhibit the improvement of photocatalytic conversion efficiency. Herein, we successfully synthesized the FAPbBr3/A-SiO2 nanocomposites photocatalyst by anchoring formamidinium (FA+, HC(NH2)2+) lead halide perovskite quantum dots on aminated silica spheres to construct the composite photocatalysts via NH chemical bonding. The FAPbBr3/A-SiO2 composites show the significantly enhanced visible-light-driven NO removal activity (70%) compared to the pristine FAPbBr3 (30%) in half an hour at room temperature, revealing that the increased active sites and efficient charge carrier separation contribute to the absorption and activation of reactant molecules. This work would open the new possibilities for improving the photocatalytic ability of perovskite quantum dots.

Nanoisozymes: The Origin behind Pristine CeO2 as Enzyme Mimetics.

It is known that the interplay between molecules and active sites on the topmost surface of a solid catalyst determines its activity in heterogeneous catalysis. The electron density of the active site is believed to affect both adsorption and activation of reactant molecules at the surface. Unfortunately, commercial X-ray photoelectron spectroscopy, which is often adopted for such characterization, is not sensitive enough to analyze the topmost surface of a catalyst. Most researchers fail to acknowledge this point during their catalytic correlation, leading to different interpretations in the literature in recent decades. Recent studies on pristine Cu2 O [Nat. Catal. 2019, 2, 889; Nat. Energy 2019, 4, 957] have clearly suggested that the electron density of surface Cu is facet dependent and plays a key role in CO2 reduction. Herein, it is shown that pristine CeO2 can reach 2506/1133 % increase in phosphatase-/peroxidase-like activity if the exposed surface is wisely selected. By using NMR spectroscopy with a surface probe, the electron density of the surface Ce (i.e., the active site) is found to be facet dependent and the key factor dictating their enzyme-mimicking activities. Most importantly, the surface area of the CeO2 morphologies is demonstrated to become a factor only if surface Ce can activate the adsorbed reactant molecules.

Low temperature high activity of M (M = Ce, Fe, Co, Ni) doped M-Mn/TiO2 catalysts for NH3-SCR and in situ DRIFTS for investigating the reaction mechanism

The loading of Mn on TiO2 for NH3-SCR has good low temperature catalytic activity and has been extensively studied. In this experiment, a series of second metals (Ce, Fe, Co, Ni) were added to modify the Mn/TiO2 mixed oxide. The experimental results show that NiMn/TiO2 has excellent catalytic activity, but the addition of Co element did not increase the catalytic activity. The excellent catalytic activity of NiMn/TiO2 is mainly due to its the strong interaction, which enhances the reducibility, increases the total acid amount, Ti3+ ratio, Mn4+ ratio, and the proportion of adsorbed oxygen. These factors facilitate the adsorption and activation of reactant molecules. In addition, in situ DRIFTS results indicate that both the B acid site and the L acid site function at 200 °C, bidentate nitrate not participate in the catalytic reaction and the Langmuir-Hinshelwood (L-H) mechanism dominates at 200 °C.

Selective oxidative esterification of alcohols over Au-Pd/graphene

Direct selective oxidative esterification of readily available alcohols under mild conditions is an attractive approach to synthesis valuable esters. Developing high performance catalyst is the key factor to the efficient esters synthesis. We report graphene supported Au-Pd alloy catalyst exhibits excellent catalytic performance in the synthesis of methyl benzoate from benzyl alcohol and methanol, a turnover frequency (TOF) of 230 h−1 and selectivity of 100% to methyl benzoate were achieved under 1 atm O2 at 25 °C, which is superior to the majority of the state-of-the-art catalysts. Experimentally observed volcano-like reactivity trends and DFT calculations prove the outstanding performance was mainly ascribed to unique electronic structures of AuPd alloy catalyst for the adsorption and activation of reactant molecules. The catalytic reaction mechanism for interpretation of the structure-activity relationships of various catalysts at molecular level was investigated. The present study could help to unravel the synergistic effect of Au-Pd catalyst and provides a mild and efficient route for synthesis high-value esters in terms of green and sustainable chemistry.

Monolayer Epitaxial Heterostructures for Selective Visible‐Light‐Driven Photocatalytic NO Oxidation

AbstractConstruction of vertical heterostructures by stacking two‐dimensional (2D) layered materials via chemical bonds can be an effective strategy to explore advanced solar‐energy‐conversion systems. However, it remains a great challenge to fabricate such heterostructures based on conversional oxide‐based compounds, as they either do not possess a 2D layered structure or are not suitable for epitaxial growth due to large lattice mismatch. Here, a vertical heterostructure of bismuth oxyhalide semiconductors fabricated through a heteroepitaxial anion exchange method is reported. Monolayer Bi2WO6 is epitaxially grown on the exposed surface of BiOI to inhibit photocorrosion and introduce active sites. Theoretical and experimental results reveal that electrons generated under visible‐light irradiation can directly transfer to surface coordinatively unsaturated (CUS) Bi atoms, which contribute to the adsorption and activation of reactant molecules. As a result, the Bi2WO6/BiOI vertical heterostructures exhibit significantly enhanced visible‐light‐driven NO oxidation activity compared with BiOI and Bi2WO6.

Preparation and Enhanced Photocatalytic Properties of 3D Nanoarchitectural ZnO Hollow Spheres with Porous Shells.

By using ginkgo leaves (GL) as template and Zn(CH3COO)2∙2H2O as Zn source, a series of ZnO samples with special morphology were prepared via a template-assisted two-steps method without adding any other additives. The degradation of the dye MB was used to evaluate the photocatalytic property of the as-prepared samples. The results showed that when a proper amount of the template was used, a 3D nanoarchitectural ZnO hollow sphere with porous sphere shell assembled by well-distributed nanoparticles was obtained and its photocatalytic activity was much higher than that of ZnO nanoparticles. The special morphology of the sample was herein considered to be very helpful for highly efficient adsorption and activation of reactant molecules by multi-times adsorption-desorption-adsorption, efficient absorption of irradiation light by repeated absorption-reflection-absorption, and efficient separation of the photogenerated e−-h+ pairs. In addition, the formation of 3D structure of sample ZnO was also discussed.

Mechanism and kinetics of sodium borohydride hydrolysis over crystalline nickel and nickel boride and amorphous nickel–boron nanoparticles

The initial hydrogen generation turnover rates during the hydrolysis of sodium borohydride over nickel catalysts (crystalline nickel (Ni), crystalline nickel boride (Ni3B), and amorphous nickel–boron (Ni–B) nanoparticles) were measured to investigate the reaction kinetics and mechanisms by varying the reactant concentrations and reaction temperatures. Nickel catalysts with and without boron follow different hydrolysis pathways; hydroxide ions are involved in the activation of reactant molecules over Ni3B and Ni–B catalysts. This study explicitly reports the zero-order and first-order reaction kinetics with respect to the reactant concentration over Ni, Ni3B and Ni–B catalysts. The initial hydrogen generation turnover rates and activation energies determined from the experimental data indicate that the amorphous Ni–B nanoparticles exhibit the highest turnover rate and lowest activation energy for the hydrolysis of borohydride among the investigated catalysts. This study provides a general strategy for the development of borohydride hydrolysis catalysts via the modification of a metal catalyst using boron, which causes the crystalline structure to become amorphous and leads to electron-rich, highly undercoordinated metal atoms at the surface.

Specifics of C-C bond formation and rearrangement in transformations of hydrocarbons on modified zeolites

Using high-performance catalysts prepared from zeolites Y, M, and ZSM-5, the dependence on the acid and micropore characteristics of modified zeolites was studied for the yields of products of dehydrocycloaromatization of C2+ alkanes, the isomerization of n-pentane, and the disproportionation of toluene. On the basis of the obtained experimental results and published data, it was shown that the initial activation of reactant molecules occurs on acid sites regardless of their acid strength and that the formation and rearrangement of C-C bonds are controlled by the molecular-sieve parameters of a zeolite and can be varied via the modification of the virgin zeolites used to prepare the catalysts.