Journal of the American Chemical Society
·
2024
·
IF 14.4
Baoxin Ni,Peng Shen,Guiru Zhang,Jiajun Zhao,Honghe Ding,Yifan Ye,Zhouying Yue,Hui Yang,Hao Wei,Kun Jiang
Pt is a well-known benchmark catalyst in the acidic oxygen reduction reaction (ORR) that drives electrochemical O2-to-H2O conversion with maximum chemical energy-to-electricity efficiency. Once dispersing bulk Pt into isolated single atoms, however, the preferential ORR pathway remains a long-standing controversy due to their complex local coordination environment and diverse site density over substrates. Herein, using a set of carbon nanotube supported Pt–N–C single-atom catalysts, we demonstrate how the neighboring N dopants regulate the electronic structure of the Pt central atom and thus steer the ORR selectivity; that is, the O2-to-H2O2 conversion selectivity can be tailored from 10% to 85% at 0.3 V versus reversible hydrogen electrode. Moreover, via a comprehensive X-ray-radiated spectroscopy and shell-isolated nanoparticle-enhanced Raman spectroscopy analysis coupled with theoretical modeling, we reveal that a dominant pyridinic- and pyrrolic-N coordination within the first shell of Pt–N–C motifs favors the 4e– ORR, whereas the introduction of a second-shell graphitic-N dopant weakens *OOH binding on neighboring Pt sites and gives rise to a dominant 2e– ORR. These findings underscore the importance of the chemical environment effect for steering the electrochemical performance of single-atom catalysts.
研究领域:
电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Xunzhu Jiang,Xiang-Ting Min,Xiaoli Pan,Botao Qiao
The development of noble-metal single atom catalysts (SACs) with low valence is highly required for many important chemical reactions such as alkene hydrosilylation, but proves to be very challenging. Herein, we report a facile strategy for the precise construction of low-valent Pt SACs by preparing 0.1Pt 1 x Re 1 /NiO with varying Re density and find that the activity of Pt-catalyzed hydrosilylation is strongly dependent on the density of Re promoters. Spectroscopic characterizations reveal the electron transfer process from Re promoters to Pt sites is facilitated by denser Re atoms, forming Pt species with less electron deficiency. During alkene hydrosilylation, Pt species modified by adjacent Re single atoms can lower energy barrier of key reduction elimination step. As a result, the 0.1Pt 1 5Re 1 /NiO SAC exhibits a TOF of 2.38 × 10 5 h -1 , a 12-fold improvement over that of pristine 0.1Pt 1 /NiO.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Chem
·
2019
·
IF 18.205
Rongan Shen,Wenxing Chen,Qing Peng,Siqi Lu,Lirong Zheng,Xing Cao,Yu Wang,Wei Zhu,Juntao Zhang,Zhongbin Zhuang,Chen Chen,Dingsheng Wang,Yadong Li
Summary The electrochemical direct synthesis of hydrogen peroxide (H 2 O 2 ) is significant but still challenging because of the lack of highly selective and active catalysts. Here, we report the synthesis of hollow nanospheres constructed by atomically dispersing platinum in amorphous CuS x support (h-Pt 1 -CuS x ) with a high concentration of single atomic Pt sites (24.8 at%), and this catalyst can consistently reduce O 2 into H 2 O 2 with selectivity of 92%–96% over a wide potential range of 0.05–0.7 V versus RHE in HClO 4 electrolyte. Scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy confirmed the atomically isolated form of Pt with a low valance of +0.75. An electrochemical device that can synthesize H 2 O 2 directly from H 2 and O 2 is fabricated with H 2 O 2 productivity as high as 546 ± 30 mol kg cat − 1 h −1 . The well-defined and high-concentration single atomic Pt sites result in ultrahigh productivity of H 2 O 2 .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Wanzhen Zhu,Yu Meng,Chaoxin Yang,Jun Zhao,Hongliang Wang,Wei Hu,Guangqiang Lv,Yingxiong Wang,Tiansheng Deng,Xianglin Hou
As the frontier in heterogeneous catalyst, a monomer and positively charged active sites in the single-atom catalyst (SAC), anchored by high electronegative N, O, S, P, etc., atoms, may not be active for the multispecies (O2, substrates, intermediates, solvent etc.) involved liquid-phase aerobic oxidation. Here, with catalytic, aerobic oxidation of 5-hydroxymethylfurfural as an example, Pt SAC (Pt1-N4) was synthesized and tested first. With commercial Pt/C (Pt loading of 5 wt %) as a benchmark, 2,5-furandicarboxylic acid (FDCA) yield of 97.6% was obtained. Pt SAC (0.56 wt %) gave a much lower FDCA yield (28.8%). By changing the coordination atoms from highly electronegative N to low electronegative Co atoms, the prepared Pt single-atom alloy (SAA, Pt1-Co3) catalyst with ultralow Pt loading (0.06 wt %) gave a much high FDCA yield (99.6%). Density functional theory (DFT) calculations indicated that positively charged Pt sites (+0.712e) in Pt1-N4 almost lost the capability for oxygen adsorption and activation, as well as the adsorption for the key intermediate. In Pt1-Co3 SAA, the central negatively charged Pt atom (−0.446e) facilitated the adsorption of the key intermediate; meanwhile, the nearby Co atoms around the Pt atom constituted the O2-preferred adsorption/activation sites. This work shows the difference between the SAC with NPs and the SAA during liquid-phase oxidation of HMF and gives a useful guide in the future single-atom catalyst design in other related reactions.
研究领域:
催化化学
·
材料科学
·
理论计算化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2025
·
IF 4.8
Xiao Yang,Heying Zhao,Aiyong Wang,Wangcheng Zhan,Yanglong Guo,Li Wang,Xuan Tang,Yun Guo
SO 2 in the sintering flue gas severely inhibits the CO oxidation performance of commercial Pt/Al 2 O 3 catalysts. However, the major poisoning mechanism of SO 2 on Pt/Al 2 O 3 in CO oxidation in the presence of H 2 O remains to be elucidated. Here, Pt/Al 2 O 3 was pretreated with different reducing atmospheres at high temperatures. Among these, the catalyst pretreated with a CO atmosphere at 600 °C (denoted as Pt/Al 2 O 3 -CO-600) exhibited superior CO oxidation performance and enhanced sulfur resistance in the presence of both H 2 O and SO 2 . The combination of XPS, HAADF-STEM, TG-MS, SO 2 oxidation test, and in-situ DRIFTS reveal that the Pt species on Pt/Al 2 O 3 -CO-600 transformed from Pt oxide clusters to metallic Pt nanoparticles. This transformation enhanced SO 2 adsorption and reactivity, leading to increased sulfate accumulation. Despite the high SO 2 reactivity and sulfate content, in-situ DRIFTS revealed that the CO reaction of Pt/Al 2 O 3 -CO-600 was less hindered by SO 2 and the sulfated Al 2 O 3 . This is attributed to the high ratio of the under-coordinated (UC) Pt sites in Pt/Al 2 O 3 -CO-600, which promotes the reaction intermediates spillover from Pt site to Al 2 O 3 compared to the Pt/Al 2 O 3 . This phenomenon was positively correlated with the sulfur resistance of reduced catalysts. Accordingly, the UC site contributes to the spillover of sulfate intermediate (H 2 SO 4 ), reducing the CO reactivity loss of Pt/Al 2 O 3 due to the intermediate coverage. This study elucidates that the primary poisoning pathway of Pt/Al 2 O 3 in the presence of H 2 O and SO 2 is the difficulty of sulfate intermediate spillover.
研究领域:
催化化学
·
环境化学
·
材料科学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Hao Zhang,Qiuye Li,Bowen Li,Bo Weng,Zhihong Tian,Jianjun Yang,Johan Hofkens,Feili Lai,Tianxi Liu
We report a porous metal–organic framework loaded with single Pt atoms, namely PCN-222(Pt) nanorods, which are prepared by the self-assembly of Pt-metalized tetrakis(4-carboxyphenyl)porphyrin ligand with a Zr 6 cluster. The mass-loading of Pt in the synthesized PCN-222(Pt) is up to 4.67%, and can be accurately controlled by using an in-situ reaction strategy. Remarkably, the PCN-222(Pt) exhibits a highly efficient photocatalytic hydrogen production rate of 614 μmol g -1 h −1 , which is 7.4 times higher than that of PCN-222 (an isostructural sample to PCN-222(Pt) without coordinated Pt ions in the porphyrin rings). The apparent quantum efficiency of PCN-222(Pt) reaches up to 1.049% at 420 nm. Electron paramagnetic resonance spectra confirm the as-formed intermediate Zr III , obtained from the reduction of Zr IV species, participates in the photocatalytic reaction. Density functional theory calculations demonstrate the positive role that single Pt atoms in PCN-222(Pt) play in optimizing the corresponding hydrogen binding energy. The existence of this dual reaction mechanism in PCN-222(Pt) greatly and synergistically boosts the photocatalytic H 2 production activity.
研究领域:
材料科学
·
催化
·
光催化
·
能量转换
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）