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Coking is the leading cause of catalyst deactivation in many important hydrocarbon conversion technologies. Understanding regeneration mechanisms is critical for developing effective carbon removal strategies that improve catalyst longevity and reduce operational costs. Here, we present a spatially resolved operando investigation of the regeneration of a spent Ni/CeO2 catalyst under industrially relevant air-like conditions, using in-situ environmental transmission electron microscopy (ETEM) combined with semantic segmentation. By deconvoluting competing gasification events for filamentous carbon removal, we found three distinct gasification modes─while fast catalytic gasification was expected, less steady noncatalytic combustion and cooperative gasification were also present and even more prevalent. Microstructure-informed kinetics directly linked the maximum gasification rates to axial filament consumption through either Ni/carbon contact or filament breakage, emphasizing the pivotal role of edge-plane carbon sites across all gasification pathways. Moreover, our operando characterization uncovered a Ni(−Cx)-limited carbon diffusion mechanism, which challenges the conventional carbon bulk diffusion model typically assumed for catalytic gasification. Furthermore, adverse processes such as Ni/carbon contact disruption and gasification-induced catalyst sintering were also identified. Collectively, these findings provide mechanistic insights into carbon gasification processes, highlighting critical pathways and potential pitfalls that can guide the optimization of catalyst regeneration strategies. 

Abstract To enhance the reaction kinetics without sacrificing activity in porous materials, one potential solution is to utilize the anisotropic distribution of pores and channels besides enriching active centers at the reactive surfaces. Herein, by designing a unique distribution of oriented pores and single crystalline array structures in the presence of abundant acid sites as demonstrated in the ZSM-5 nanorod arrays grown on monoliths, both enhanced dynamics and improved capacity are exhibited simultaneously in propene capture at low temperature within a short duration. Meanwhile, the ZSM-5 array also helps mitigate the long-chain HCs and coking formation due to the enhanced diffusion of reactants in and reaction products out of the array structures. Further integrating the ZSM-5 array with Co₃O₄nanoarray enables comprehensive propene removal throughout a wider temperature range. The array structured film design could offer energy-efficient solutions to overcome both sorption and reaction kinetic restrictions in various solid porous materials for various energy and chemical transformation applications. 

TiO 2 supported catalysts have been widely studied for the selective catalytic reduction (SCR) of NO x ; however, comprehensive understanding of synergistic interactions in multi-component SCR catalysts is still lacking. Herein, transition metal elements (V, Cr, Mn, Fe, Co, Ni, Cu, La, and Ce) were loaded onto TiO 2 nanoarrays via ion-exchange using protonated titanate precursors. Amongst these catalysts, Mn-doped catalysts outperform the others with satisfactory NO conversion and N 2 selectivity. Cu co-doping into the Mn-based catalysts promotes their low-temperature activity by improving reducibility, enhancing surface Mn 4+ species and chemisorbed labile oxygen, and elevating the adsorption capacity of NH 3 and NO x species. While Ce co-doping with Mn prohibits the surface adsorption and formation of NH 3 and NO x derived species, it boosts the N 2 selectivity at high temperatures. By combining Cu and Ce as doping elements in the Mn-based catalysts, both the low-temperature activity and the high-temperature N 2 selectivity are enhanced, and the Langmuir–Hinshelwood reaction mechanism was proved to dominate in the trimetallic Cu–Ce–5Mn/TiO 2 catalysts due to the low energy barrier. 

Abstract Converting CO₂to value‐added chemicals,e. g., CH₃OH, is highly desirable in terms of the carbon cycling while reducing CO₂emission from fossil fuel combustion. Cu‐based nanocatalysts are among the most efficient for selective CO₂‐to‐CH₃OH transformation; this conversion, however, suffers from low reactivity especially in the thermodynamically favored low temperature range. We herein report ultrasmall copper (Cu) nanocatalysts supported on crystalline, mesoporous zinc oxide nanoplate (Cu@mZnO) with notable activity and selectivity of CO₂‐to‐CH₃OH in the low temperature range of 200–250 °C. Cu@mZnO nanoplates are prepared based on the crystal‐crystal transition of mixed Cu and Zn basic carbonates to mesoporous metal oxides and subsequent hydrogen reduction. Under the nanoconfinement of mesopores in crystalline ZnO frameworks, ultrasmall Cu nanoparticles with an average diameter of 2.5 nm are produced. Cu@mZnO catalysts have a peak CH₃OH formation rate of 1.13 mol h⁻¹per 1 kg under ambient pressure at 246 °C, about 25 °C lower as compared to that of the benchmark catalyst of Cu−Zn−Al oxides. Our new synthetic strategy sheds some valuable insights into the design of porous catalysts for the important conversion of CO₂‐to‐CH₃OH.