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Simultaneously boosting the activity and selectivity of CO2 reduction catalysts remains a challenge. In this work, surface-adsorbed hydroxyl (OHad) on the SnO promoted CO2 reduction into formate th...

Nitrogen reduction reaction (NRR) under ambient conditions is always a long-standing challenge in science, due to the extreme difficulty in breaking the strong N N triple bond. The key to resolving this issue undoubtedly lies in searching superior catalysts to efficiently activate and hydrogenate the stable nitrogen molecules. We herein evaluate the feasibility of WP2 for N2 activation and reduction, and first demonstrate WP2 with an impressive ammonia yield rate of 7.13 μg h−1 cm−2, representing a promising W-based catalyst for NRR. DFT analysis further reveals that the NRR catalysis on WP2 proceeds in a distal reaction pathway, and the exceptional NRR activity is originated from superior surface electron energy level matching between WP2 and NRR potential which facilitates the interfacial proton-coupled electron transfer dynamics. The successfully unraveling the intrinsic catalytic mechanism of WP2 for NRR could offer a powerful platform to manipulate the NRR activity by tuning the electron energy levels.

The high unoccupied d band energy of Ni3N basically results in weak orbital coupling with water molecule, consequently leading to slow water dissociation kinetics. Herein, we demonstrate Cr doping can downshift the unoccupied d orbitals and strengthen the interfacial orbital coupling to boost the water dissociation kinetics. The prepared Cr-Ni3N/Ni displays an impressive overpotential of 37 mV at 10 mA·cmgeo−2, close to the benchmark Pt/C in 1.0 M KOH solution. Refined structural analysis reveals the Cr dopant exists as the Cr-N6 states and the average d band energy of Ni3N is also lowered. Density functional theory calculation further confirms the downshifted d band energy can strengthen the orbital coupling between the unpaired electrons in O 2p and the unoccupied state of Ni 3d, which thus facilitates the water adsorption and dissociation. The work provides a new concept to achieve on-demand functions for hydrogen evolution catalysis and beyond, by regulating the interfacial orbital coupling.

Although computational studies have demonstrated that metal ion doping can effectively narrow the bandgap of TiO2, the visible-light photoactivity of metal-doped TiO2 photoanodes is still far from satisfactory. Herein, we report an effective strategy to activate the visible-light photoactivity of chromium-implanted TiO2 via the incorporation of oxygen vacancies. The chromium-doped TiO2 activated by oxygen vacancies (Cr-TiO2-vac) exhibited an incident photon-to-electron conversion efficiency (IPCE) of ~6.8% at 450 nm, which is one of the best values reported for metal-doped TiO2. Moreover, Cr-TiO2-vac showed no obvious photocurrent decay after 100 h under visible-light illumination.

Tungsten oxide with strong acid resistance and weak O-binding ability could potentially achieve a tradeoff on the O-binding properties by constructing W and Ir dual sites for acidic oxygen evolution reaction (OER) catalysis. However, the peroxide intermediate formed during the OER process could react with tungsten oxide to produce soluble species, thereby severely limiting its application. Herein, we construct Ir–W@Ir–WO3−x core–shell nanoparticles with an Ir–W metallic core and an Ir-doped WO3−x (Ir–WO3−x) shell, which can deliver an impressive overpotential of 261 mV at 10 mA cm−2 for acidic OER catalysis and extraordinary catalytic stability. Spectroscopic analysis manifests that Ir–W@Ir–WO3−x could substantially suppress peroxide species formation and effectively avoid peroxide-induced corrosion during the OER process. Theoretical studies reveal that the moderate O-binding capability on Ir–W@Ir–WO3−x not only accelerates catalytic kinetics, but also restrains hydroperoxide formation. This work sheds light on the rational design of OER catalysts by modulating the adsorption behavior of oxygen-containing intermediates.

The interstitial structure and weak Ni-N interaction of Ni3N lead to high unoccupied d orbital energy and unsuitable orbital orientation, which consequently results in weak orbital coupling with H2O and slow water dissociation kinetics for alkaline hydrogen evolution catalysis. Herein, we successfully lower the unoccupied d orbital energy of Ni3N to strengthen the interfacial electronic coupling by employing the strong electron pulling capability of oxygen dopants. The prepared O-Ni3N catalyst delivers an overpotential of 55 mV at 10 mA cm−2, very close to the commercial Pt/C. Refined structural characterization indicates the oxygen incorporation can decrease the electron densities around the Ni sites. Moreover, density functional theory calculation further proves the oxygen incorporation can create more unoccupied orbitals with lower energy and superior orientation for water adsorption and dissociation. The concept of orbital-regulated interfacial electronic coupling could offer a unique approach for the rational design of hydrogen evolution catalysts and beyond.

Summary Evaporation-condensation of red phosphorous to prepare phosphorous-based anodes inevitably generates white P residual, severely limiting its practical application due to the serious safety concern. Rather than removing the white P residual by complicated post-treatments, essentially prohibiting the generation of white P is a more meaningful alternative, but unfortunately it has been rarely studied so far. Herein, we demonstrate that the generation of white P can be substantially suppressed via sulfur-mediated phosphorous activation. Moreover, the prepared sulfur-doped P also exhibits the ever-reported fastest redox kinetics for sodium-ion storage. Electron spin resonance spectra and density functional theory calculations reveal that the introduced sulfur lives in the high-spin state during the evaporation-condensation process, which could activate P4 for polymerization. Meanwhile, sulfur-induced electron delocalization can also accelerate the Na-P redox kinetics. The capability to modulate phosphorus polymerization via the high-spin mediator could revolutionize the application of phosphorous for batteries and beyond.

Molybdenum disulfide is naturally inert for alkaline hydrogen evolution catalysis, due to its unfavorable water adsorption and dissociation feature originated from the unsuitable orbital orientation. Herein, we successfully endow molybdenum disulfide with exceptional alkaline hydrogen evolution capability by carbon-induced orbital modulation. The prepared carbon doped molybdenum disulfide displays an unprecedented overpotential of 45 mV at 10 mA cm−2, which is substantially lower than 228 mV of the molybdenum disulfide and also represents the best alkaline hydrogen evolution catalytic activity among the ever-reported molybdenum disulfide catalysts. Fine structural analysis indicates the electronic and coordination structures of molybdenum disulfide have been significantly changed with carbon incorporation. Moreover, theoretical calculation further reveals carbon doping could create empty 2p orbitals perpendicular to the basal plane, enabling energetically favorable water adsorption and dissociation. The concept of orbital modulation could offer a unique approach for the rational design of hydrogen evolution catalysts and beyond., Technologies allowing for sustainable hydrogen production will contribute to the decarbonization of the future energy supply. Here the authors report that carbon induced orbital modulation can facilitate the otherwise inert MoS2 electrocatalyst superior alkaline hydrogen evolution reactivity.

Although Ni3N possesses superior hydrogen desorption behavior, its alkaline hydrogen evolution reaction (HER) catalysis is substantially hindered, due to the high-lying unoccupied orbital center induced sluggish water dissociation kinetics. Herein, we successfully endow Ni3N with exceptional alkaline HER activity by in situ interfacial engineering. The prepared Ni3N/MoO2 interfacial system delivers an ultra-small overpotential of 21 mV at 10 mA cm−2, which is very close to that of the benchmark Pt/C catalysts. Density functional theory (DFT) calculations reveal that MoO2 with a lower unoccupied orbital center could substantially boost the water dissociation kinetics, while the hydrogen desorption proceeds on Ni3N. The capability to understand and design interfacial systems provides an effective pathway for the rational construction of HER catalysts and beyond.

Manipulating the thermal decomposition behavior of energetic materials is the key to further pushing the combustion performance of solid rocket propellants. Herein, atomically dispersed Pb single atoms on polydopamine (PDA‐Pb) are demonstrated, which display unprecedented catalytic activity toward the thermal decomposition of cyclotrimethylenetrinitramine (RDX). Impressively, RDX‐based propellants with the addition of PDA‐Pb catalyst exhibit substantially enhanced burning rates (14.98 mm s−1 at 2 MPa), which is 4.8 times faster than that without PDA‐Pb and represents the best catalytic performance among Pb‐based catalysts. Moreover, it also possesses low‐pressure exponents in broad pressure ranges, which can enable more stable and safer combustion in solid rocket engines. Theoretical calculation unravels the efficient catalytic activity is stemmed from the enhanced interfacial electronic coupling between RDX and PDA‐Pb via orbital level engineering. More importantly, PDA‐Pb also presents similar catalytic behavior toward the decomposition of nitrocellulose, suggesting its broad catalytic generality. This work can open up new opportunities in the field of energetic compound combustion by exploring Pb‐based single atom catalysts and beyond., Atomically dispersed Pb single atoms on polydopamine (PDA‐Pb) display excellent catalytic activity towards the thermal decomposition of energetic materials. The addition of PDA‐Pb can substantially decrease the thermal decomposition temperature and consequently boost the burning rate of the propellants. Theoretical calculations reveal the efficient catalytic activity is stemmed from the enhanced interfacial electronic coupling via orbital level engineering.

Hydrogen evolution reaction (HER) is more sluggish in alkaline than in acidic media because of the additional energy required for water dissociation. Numerous catalysts, including NiO, that offer active sites for water dissociation have been extensively investigated. Yet, the overall HER performance of NiO is still limited by lacking favorable H adsorption sites. Here we show a strategy to activate NiO through carbon doping, which creates under-coordinated Ni sites favorable for H adsorption. DFT calculations reveal that carbon dopant decreases the energy barrier of Heyrovsky step from 1.17 eV to 0.81 eV, suggesting the carbon also serves as a hot-spot for the dissociation of water molecules in water-alkali HER. As a result, the carbon doped NiO catalyst achieves an ultralow overpotential of 27 mV at 10 mA cm−2, and a low Tafel slope of 36 mV dec−1, representing the best performance among the state-of-the-art NiO catalysts., While H2 evolution from water may serve as a renewable source of fuel, there are a limited number of catalysts that are stable and active in alkaline media. Here, authors find carbon doping of NiO to increase the number of favorable sites for H2 evolution and boost electrocatalytic performances.

The HER activities of P-rich transition metal phosphides can be substantially boosted by N-induced lattice contraction., P-rich transition metal phosphides (TMPs) with abundant P sites have been predicted to be more favorable for hydrogen evolution reaction (HER) catalysis. However, the actual activities of P-rich TMPs do not behave as expected, and the underlying essence especially at the atomic level is also ambiguous. Our structural analysis reveals the inferior activity could stem from the reduced overlap of atomic wave functions between metal and P with the increase in P contents, which consequently results in too strong P-H interaction. To this end, we used N-induced lattice contraction to generally boost the HER catalysis of P-rich TMPs including CoP2, FeP2, NiP2, and MoP2. Refined structural characterization and theoretical analysis indicate the N-P strong interaction could increase the atomic wave function overlap and eventually modulate the H adsorption strength. The concept of lattice engineering offers a new vision for tuning the catalytic activities of P-rich TMPs and beyond.

Metal sulfides for hydrogen evolution catalysis typically suffer from unfavorable hydrogen desorption properties due to the strong interaction between the adsorbed H and the intensely electronegative sulfur. Here, we demonstrate a general strategy to improve the hydrogen evolution catalysis of metal sulfides by modulating the surface electron densities. The N modulated NiCo2S4 nanowire arrays exhibit an overpotential of 41 mV at 10 mA cm−2 and a Tafel slope of 37 mV dec−1, which are very close to the performance of the benchmark Pt/C in alkaline condition. X-ray photoelectron spectroscopy, synchrotron-based X-ray absorption spectroscopy, and density functional theory studies consistently confirm the surface electron densities of NiCo2S4 have been effectively manipulated by N doping. The capability to modulate the electron densities of the catalytic sites could provide valuable insights for the rational design of highly efficient catalysts for hydrogen evolution and beyond. The hydrogen evolution reaction is a promising route to produce clean hydrogen fuel; however, its efficient electrolytic generation relies on expensive platinum. Here, the authors show how modulating electron density in a metal sulfide, NiCo2S4, boosts hydrogen desorption to achieve high catalytic activity.

Endowing materials with specific functions that are not readily available is always of great importance, but extremely challenging. Co4 N, with its beneficial metallic characteristics, has been proved to be highly active for the oxidation of water, while it is notoriously poor for catalyzing the hydrogen evolution reaction (HER), because of its unfavorable d-band energy level. Herein, we successfully endow Co4 N with prominent HER catalytic capability by tailoring the positions of the d-band center through transition-metal doping. The V-doped Co4 N nanosheets display an overpotential of 37 mV at 10 mA cm-2 , which is substantially better than Co4 N and even close to the benchmark Pt/C catalysts. XANES, UPS, and DFT calculations consistently reveal the enhanced performance is attributed to the downshift of the d-band center, which helps facilitate the H desorption. This concept could provide valuable insights into the design of other catalysts for HER and beyond.

Building the fundamental relation between the polysulfides adsorption on cathode additives and Li S chemistry kinetics is critical for the rational design of efficient and reliable Li S batteries. Herein, we reveal that Li S chemistry kinetics can be well regulated by manipulating the electron-filling state of d orbitals in Ta2O5. The prepared S@N-Ta2O5/rGO with moderate N contents delivers the lowest polarization for LiPSs conversion and the highest specific capacity of 1252.8 mAh g−1 at 0.2C. More importantly, the theoretical analysis unravel that the enhanced electrochemical performance is mainly originated from the orbital-induced adsorption modulation. This work could offer a powerful platform to manipulate the Li S chemistry by orbital engineering for high-performance Li S batteries.

The capability of manipulating the interfacial electronic coupling is the key to achieving on-demand functionalities of catalysts. Herein, it is demonstrated that the electronic coupling of Fe2 N can be effectively regulated for hydrogen evolution reaction (HER) catalysis by vacancy-mediated orbital steering. Ex situ refined structural analysis reveals that the electronic and coordination states of Fe2 N can be well manipulated by nitrogen vacancies, which impressively exhibit strong correlation with the catalytic activities. Theoretical studies further indicate that the nitrogen vacancy can uniquely steer the orbital orientation of the active sites to tailor the electronic coupling and thus benefit the surface adsorption capability. This work sheds light on the understanding of the catalytic mechanism in real systems and could contribute to revolutionizing the current catalyst design for HER and beyond.

Although it is commonly believed that the water-dissociation-related Volmer process is the rate-limiting step for alkaline hydrogen evolution reaction (HER) on Pt-based catalysts, the underlying essence, particularly on the atomic scale, still remains unclear. Herein, it is revealed that the sluggish water-dissociation behavior probably stems from unfavorable orbital orientation and the kinetic issue is successfully resolved via N-induced orbital tuning. Impressively, N modified Pt-Ni nanowires deliver an ultralow overpotential of 13 mV at 10 mA cm-2 , which represents a new benchmark for alkaline HER catalysis. Fine-structural characterization and density functional theory analysis illustrate that the introduced nitrogen can uniquely modulate the electron densities around the Ni sites, and further create empty dz 2 orbitals with superior orientation for water adsorption and activation. More importantly, it is demonstrated that N-induced orbital modulation can generally boost the alkaline HER activities of Pt-Co, Pt-Ni, and Pt-Cu, offering a new perspective for the design of HER catalysts and beyond.