scholarly journals Controllable H2 Generation by Formic Acid Decomposition on a Novel Pd/Templated Carbon Catalyst

Hydrogen ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 22-37
Author(s):  
Maria Mihet ◽  
Monica Dan ◽  
Lucian Barbu-Tudoran ◽  
Mihaela D. Lazar ◽  
Gabriela Blanita

A novel Pd/templated carbon catalyst (Pd/TC) was developed, characterized, and tested in the dehydrogenation of formic acid (FA) under mild conditions, with the possibility to control the H2 generation rate, in the absence or presence of HCOONa (SF), by adjusting the Pd:FA and/or FA:SF ratios. The characterization results of the templated carbon obtained by the chemical vapor deposition of acetylene on NaY zeolite revealed different structural and morphological properties compared to other C-based supports. Therefore, it was expected to induce a different catalytic behavior for the Pd/TC catalyst. Indeed, the TC-supported Pd catalyst exhibited superior activity in the decomposition of FA, even at room temperature, with turnover frequencies (TOFs) of up to 143.7 and 218.8 h−1 at 60 °C. The H2 generation rate increased with an increasing temperature, while the H2 yield increased with a decreasing FA concentration. Constant generation of gaseous flow (H2 + CO2) was achieved for 11 days, by the complete dehydrogenation of FA at room temperature using a 2 M FA solution and Pd:FA = 1:2100. The presence of SF in the reaction medium significantly enhanced the H2 generation rate (535 h−1 for FA:SF = 3:1 and 60 °C).

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3577 ◽  
Author(s):  
Alexey Pechenkin ◽  
Sukhe Badmaev ◽  
Vladimir Belyaev ◽  
Vladimir Sobyanin

Formic acid decomposition to H2-rich gas was investigated over a CuO-CeO2/γ-Al2O3 catalyst. The catalyst was characterized by XRD, HR TEM and EDX methods. A 100% conversion of formic acid was observed over the copper-ceria catalyst under ambient pressure, at 200–300 °C, N2:HCOOH = 75:25 vol.% and flow rate 3500–35,000 h−1 with H2 yield of 98%, wherein outlet CO concentration is below the equilibrium data (<0.5 vol.%). The copper-ceria catalyst proved to be promising for multifuel processor application, and the H2 generation from dimethoxymethane, methanol, dimethyl ether and formic acid on the same catalyst for fuel cell supply.


2021 ◽  
Author(s):  
Amit Gautam ◽  
Saddam Sk ◽  
Amritanjali Tiwari ◽  
Moses Abraham Bokinala ◽  
P. Vijayanand ◽  
...  

A highly efficient hybrid ZnCdS-rGO/MoS2 heterostructure is successfully synthesized through a hot injection approach and control loading of rGO/MoS2. The synergism provides an unprecedently high H2-generation rate 193.4 mmol H2...


2021 ◽  
Vol 2 (1) ◽  
pp. 39-48
Author(s):  
Nguyen H. H. Phuc ◽  
Takaki Maeda ◽  
Tokoharu Yamamoto ◽  
Hiroyuki Muto ◽  
Atsunori Matsuda

A solid solution of a 100Li3PS4·xLi3PO4 solid electrolyte was easily prepared by liquid-phase synthesis. Instead of the conventional solid-state synthesis methods, ethyl propionate was used as the reaction medium. The initial stage of the reaction among Li2S, P2S5 and Li3PO4 was proved by ultraviolet-visible spectroscopy. The powder X-ray diffraction (XRD) results showed that the solid solution was formed up to x = 6. At x = 20, XRD peaks of Li3PO4 were detected in the prepared sample after heat treatment at 170 °C. However, the samples obtained at room temperature showed no evidence of Li3PO4 remaining for x = 20. Solid phosphorus-31 magic angle spinning nuclear magnetic resonance spectroscopy results proved the formation of a POS33− unit in the sample with x = 6. Improvements of ionic conductivity at room temperature and activation energy were obtained with the formation of the solid solution. The sample with x = 6 exhibited a better stability against Li metal than that with x = 0. The all-solid-state half-cell employing the sample with x = 6 at the positive electrode exhibited a better charge–discharge capacity than that employing the sample with x = 0.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3258
Author(s):  
Hamed M. Alshammari ◽  
Mohammad Hayal Alotaibi ◽  
Obaid F. Aldosari ◽  
Abdulellah S. Alsolami ◽  
Nuha A. Alotaibi ◽  
...  

The present study investigates a process for the selective production of hydrogen from the catalytic decomposition of formic acid in the presence of iridium and iridium–palladium nanoparticles under various conditions. It was found that a loading of 1 wt.% of 2% palladium in the presence of 1% iridium over activated charcoal led to a 43% conversion of formic acid to hydrogen at room temperature after 4 h. Increasing the temperature to 60 °C led to further decomposition and an improvement in conversion yield to 63%. Dilution of formic acid from 0.5 to 0.2 M improved the decomposition, reaching conversion to 81%. The reported process could potentially be used in commercial applications.


Chemosensors ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 32
Author(s):  
Pei-Cheng Jiang ◽  
Yu-Ting Chow ◽  
Chi-Wei Chien ◽  
Cheng-Hsun-Tony Chang ◽  
Chii-Ruey Lin

Silica (SiO2, silicon dioxide—a dielectric layer commonly used in electronic devices) is widely used in many types of sensors, such as gas, molecular, and biogenic polyamines. To form silica films, core shell or an encapsulated layer, silane has been used as a precursor in recent decades. However, there are many hazards caused by using silane, such as its being extremely flammable, the explosive air, and skin and eye pain. To avoid these hazards, it is necessary to spend many resources on industrial safety design. Thus, the silica synthesized without silane gas which can be determined as a silane-free procedure presents a clean and safe solution to manufactures. In this report, we used the radio frequency (rf = 13.56 MHz) plasma-enhanced chemical vapor deposition technique (PECVD) to form a silica layer at room temperature. The silica layer is formed in hydrogen-based plasma at room temperature and silane gas is not used in this process. The substrate temperature dominates the silica formation, but the distance between the substrate and electrode (DSTE) and the methane additive can enhance the formation of a silica layer on the Si wafer. This silane-free procedure, at room temperature, is not only safer and friendlier to the environment but is also useful in the fabrication of many types of sensors.


2021 ◽  
Vol 7 (16) ◽  
pp. eabf7358
Author(s):  
Meng Peng ◽  
Runzhang Xie ◽  
Zhen Wang ◽  
Peng Wang ◽  
Fang Wang ◽  
...  

Blackbody-sensitive room-temperature infrared detection is a notable development direction for future low-dimensional infrared photodetectors. However, because of the limitations of responsivity and spectral response range for low-dimensional narrow bandgap semiconductors, few low-dimensional infrared photodetectors exhibit blackbody sensitivity. Here, highly crystalline tellurium (Te) nanowires and two-dimensional nanosheets were synthesized by using chemical vapor deposition. The low-dimensional Te shows high hole mobility and broadband detection. The blackbody-sensitive infrared detection of Te devices was demonstrated. A high responsivity of 6650 A W−1 (at 1550-nm laser) and the blackbody responsivity of 5.19 A W−1 were achieved. High-resolution imaging based on Te photodetectors was successfully obtained. All the results suggest that the chemical vapor deposition–grown low-dimensional Te is one of the competitive candidates for sensitive focal-plane-array infrared photodetectors at room temperature.


2021 ◽  
pp. 2000212
Author(s):  
Krishnan Ravi ◽  
Dhanaji R. Naikwadi ◽  
Balasaheb D. Bankar ◽  
Ankush V. Biradar
Keyword(s):  

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