When the nature of surface functionalities on modified carbon dominates the dispersion of palladium hydrogenation catalysts

Castillejos, Eva; García-Minguillán, A. M.; Bachiller‐Baeza, B.; Rodrı́guez-Ramos, I.; Guerrero-Ruı́z, A.

doi:10.1016/j.cattod.2017.05.024

Cited by 20 publications

(10 citation statements)

References 32 publications

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“…Characterization suggested that plasma treatment on Nb 2 O 5 did not change its crystalline structure; however, an improved uniformity of support pores (Figure and Figure (a) and (c)) and an enhanced hydrophilicity (Figure (b) and (d) and Figure S1, SI) were observed on the N(P) sample. Both improved pore uniformity and more surface functional groups (hydrophilic) on support material are beneficial for the more homogeneous dispersion of smaller cobalt species; − indeed, based on XRD, TEM, and HAADF results (Figure and Figure ), an enhanced cobalt dispersion with narrower particle size distribution is presented on N(P) supported catalysts, in comparison with their N supported counterparts.…”

Section: Results and Discussionmentioning

confidence: 93%

Preparation of Highly Dispersed Nb₂O₅ Supported Cobalt-Based Catalysts for the Fischer–Tropsch Synthesis

Xiao

Han

Jing

et al. 2020

Ind. Eng. Chem. Res.

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In this work, niobia supported cobalt catalysts with both high cobalt dispersion and high cobalt loading (15 wt %) were prepared through the assistance of glow discharge plasma treatment, and their catalytic performance was tested in Fischer− Tropsch synthesis (FTS). Plasma treatment on support and especially on the decomposition of the catalyst precursor leads to a noticeable enhancement of cobalt dispersion. However, in addition to the cobalt dispersion improvement, plasma assisted decomposition of the cobalt precursor also led to the formation of CoNb 2 O 5 , which was inactive in FTS; moreover, the small cobalt particles underwent severe sintering during the reaction and caused significant and contineous deactivation. Plasma treatment on nobia could modify its porosity and hydrophilicity and generate surface functional groups; these features enabled an improved cobalt-niobia interaction and better cobalt dispersion on CoN(P)-C than on CoN-C. The enhanced FTS activity and best reaction stability on the CoN(P)-C catalyst were due to the possession of a suitable cobalt particle size and moderate cobalt-niobia interaction.

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Section: Results and Discussionmentioning

confidence: 93%

Preparation of Highly Dispersed Nb₂O₅ Supported Cobalt-Based Catalysts for the Fischer–Tropsch Synthesis

Xiao

Han

Jing

et al. 2020

Ind. Eng. Chem. Res.

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“…Notably, the specific surface area of the material was found to increase with the amount of metal precursors, which is possible because more acetate anions generate large amounts of gas in air at 400 °C leading to an increase in both their specific surface area and pore volume (Table ). ,− Subsequently, CO 2 adsorption tests were conducted on Al 2 O 3 , Pd 0.25 Cu 0.75 /Al 2 O 3 -0.1, and Pd 0.25 Cu 0.75 /Al 2 O 3 –0.4 at 25 °C (Figure c). It is worth noting that Al 2 O 3 , Pd 0.25 Cu 0.75 /Al 2 O 3 -0.1, and Pd 0.25 Cu 0.75 /Al 2 O 3 -0.4 all have better adsorption performance on CO 2 , which might benefit from their advantages of large specific surface area, rich mesoporous structure, and surface basic sites. ,− The adsorption capacity of the catalysts for CO 2 increase with the enhancement of the metal precursor amount.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Mesoporous Pd_xCu_1–x/Al₂O₃-y Bimetallic Catalysts Via Mechanochemistry for Selective N-Formylation of Amines with CO₂ and H₂

Zou

Chen

Wang

et al. 2021

ACS Sustainable Chem. Eng.

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We herein reported an effective strategy for the preparation of bimetallic mesoporous catalysts Pd x Cu1–x /Al2O3-y via mechanochemistry. The resulting Pd0.25Cu0.75/Al2O3 catalyst showed excellent catalytic activity and good selectivity for N-formylation of various aliphatic amines with CO2 and H2. Compared to previously reported heterogeneous catalysts for N-formylation, Pd0.25Cu0.75/Al2O3-0.1 demonstrates the lowest Pd loading but still achieves an unprecedented turnover number up to 527. Further mechanistic studies suggest that carbamate and formate are critical intermediates in N-formylation of amines with CO2 and H2 over a catalyst of Pd0.25Cu0.75/Al2O3. This mechanochemical strategy provides an opportunity for green and economical synthesis of heterogeneous metal catalysts.

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“…Besides the lower amount of total oxygen groups observed for ZnCPd and FeCPd, the more remarkable difference is the absence, or very small amount of carbonyl/quinone groups in these catalysts. The presence of these groups may promote hydrogenation reactions by favouring adsorption of reactants and thus reaction with the surrounding H 2 [34][35][36] . The high concentrations of the aforementioned groups on the surface of NaCPd and KCPd catalysts may enhance the extent of hydrogenation of the adsorbed radicals leading to a higher proportion of ethane and propane instead of ethylene and propylene (Table 1).…”

Section: Resultsmentioning

confidence: 99%

Selectivity to Olefins in the Hydrodechlorination of Chloroform with Activated Carbon-Supported Palladium Catalysts

Fernandez-Ruiz

Bedia

Andreoli

et al. 2019

Ind. Eng. Chem. Res.

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This study analyzes the selectivity of Pd (1 wt%) catalysts supported on different activated carbons to produce olefins from hydrodechlorination of chloroform. It was found that selectivity to olefins was favoured by a higher zero-valent to electrodeficient Pd ratio (Pd 0 /Pd n+) and by a lower amount of oxygen-containing surface functional groups on the activated carbon supports. Thus, the highest selectivity to olefins was obtained by catalysts supported on FeCl 3 and ZnCl 2-activated carbons. Conversely, the catalysts supported on KOH-, NaOH-, and H 3 PO 4-activated carbons gave the lowest selectivity to olefins. These catalysts showed higher surface concentrations of electro-deficient Pd as well as high concentrations of oxygen functional groups that enhance the adsorption of reactants and intermediates. This leads to complete hydrogenation of reaction intermediates and poisoning of active sites by the adsorption of chlorocarbon compounds. ZnCl 2-derived catalysts with the highest selectivity to olefins also showed an outstanding

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When the nature of surface functionalities on modified carbon dominates the dispersion of palladium hydrogenation catalysts

Cited by 20 publications

References 32 publications

Preparation of Highly Dispersed Nb₂O₅ Supported Cobalt-Based Catalysts for the Fischer–Tropsch Synthesis

Preparation of Highly Dispersed Nb₂O₅ Supported Cobalt-Based Catalysts for the Fischer–Tropsch Synthesis

Synthesis of Mesoporous Pd_xCu_1–x/Al₂O₃-y Bimetallic Catalysts Via Mechanochemistry for Selective N-Formylation of Amines with CO₂ and H₂

Selectivity to Olefins in the Hydrodechlorination of Chloroform with Activated Carbon-Supported Palladium Catalysts

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When the nature of surface functionalities on modified carbon dominates the dispersion of palladium hydrogenation catalysts

Cited by 20 publications

References 32 publications

Preparation of Highly Dispersed Nb2O5 Supported Cobalt-Based Catalysts for the Fischer–Tropsch Synthesis

Preparation of Highly Dispersed Nb2O5 Supported Cobalt-Based Catalysts for the Fischer–Tropsch Synthesis

Synthesis of Mesoporous PdxCu1–x/Al2O3-y Bimetallic Catalysts Via Mechanochemistry for Selective N-Formylation of Amines with CO2 and H2

Selectivity to Olefins in the Hydrodechlorination of Chloroform with Activated Carbon-Supported Palladium Catalysts

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Preparation of Highly Dispersed Nb₂O₅ Supported Cobalt-Based Catalysts for the Fischer–Tropsch Synthesis

Preparation of Highly Dispersed Nb₂O₅ Supported Cobalt-Based Catalysts for the Fischer–Tropsch Synthesis

Synthesis of Mesoporous Pd_xCu_1–x/Al₂O₃-y Bimetallic Catalysts Via Mechanochemistry for Selective N-Formylation of Amines with CO₂ and H₂