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Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 503
Author(s):  
Qiangu Yan ◽  
Timothy Ketelboeter ◽  
Zhiyong Cai

Nickel (Ni)-lignin nanocomposites were synthesized from nickel nitrate and kraft lignin then catalytically graphitized to few-layer graphene-encapsulated nickel nanoparticles (Ni@G). Ni@G nanoparticles were used for catalytic decomposition of methane (CDM) to produce COx-free hydrogen and graphene nanoplatelets. Ni@G showed high catalytic activity for methane decomposition at temperatures of 800 to 900 °C and exhibited long-term stability of 600 min time-on-stream (TOS) without apparent deactivation. The catalytic stability may be attributed to the nickel dispersion in the Ni@G sample. During the CDM reaction process, graphene shells over Ni@G nanoparticles were cracked and peeled off the nickel cores at high temperature. Both the exposed nickel nanoparticles and the cracked graphene shells may participate the CDM reaction, making Ni@G samples highly active for CDM reaction. The vacancy defects and edges in the cracked graphene shells serve as the active sites for methane decomposition. The edges are continuously regenerated by methane molecules through CDM reaction.


Author(s):  
Wenchao Lian ◽  
Mo Yingyu ◽  
Libin Lei ◽  
Yongzheng Ou ◽  
Ruiming Qiu ◽  
...  

Ammonia (NH3) as a carbon-free hydrogen carrier shows great potential as fuel and its production at mild conditions is desired. NH3 synthesis at atmospheric pressure can be realized in solid-state...


Ceramist ◽  
2021 ◽  
Vol 24 (4) ◽  
pp. 424-437
Author(s):  
Seokhee Lee ◽  
Sang Won Lee ◽  
Suji Kim ◽  
Tae Ho Shin

High temperature electrolysis is a promising option for carbon-free hydrogen production and huge energy storage with high energy conversion efficiencies from renewable and nuclear resources. Over the past few decades, yttria-stabilized zirconia (YSZ) based ion conductor has been widely used as a solid electrolyte in solid oxide electrolysis cells (SOECs). However, its high operation temperature and lower conductivity in the appropriate temperature range for solid electrochemical devices were major drawbacks. Regarding improving ionic-conducting electrolytes, several groups have contributed significantly to developing and applying LaGaO3 based perovskite as a superior ionic conductor. La(Sr)Ga(Mg)O3 (LSGM) electrolyte was successfully validated for intermediate-temperature solid oxide fuel cells (SOFCs) but was rarely conducted on SOECs for its high efficient electrolysis performance. Their lower mechanical strengths or higher reactivity with electrode compared with the YSZ electrolysis cells, which make it difficult to choose compatible materials, remain major challenges. In this field, SOECs have attracted a great attention in the last few years, as they offer significant power and higher efficiencies compared to conventional YSZ based electrolysers. Herein, SOECs using LSGM based electrolyte, their applications, high performance, and their issues will be reviewed.


Ceramist ◽  
2021 ◽  
Vol 24 (4) ◽  
pp. 424-437
Author(s):  
Seokhee Lee ◽  
Sang Won Lee ◽  
Suji Kim ◽  
Tae Ho Shin

High temperature electrolysis is a promising option for carbon-free hydrogen production and huge energy storage with high energy conversion efficiencies from renewable and nuclear resources. Over the past few decades, yttria-stabilized zirconia (YSZ) based ion conductor has been widely used as a solid electrolyte in solid oxide electrolysis cells (SOECs). However, its high operation temperature and lower conductivity in the appropriate temperature range for solid electrochemical devices were major drawbacks. Regarding improving ionic-conducting electrolytes, several groups have contributed significantly to developing and applying LaGaO3 based perovskite as a superior ionic conductor. La(Sr)Ga(Mg)O3 (LSGM) electrolyte was successfully validated for intermediate-temperature solid oxide fuel cells (SOFCs) but was rarely conducted on SOECs for its high efficient electrolysis performance. Their lower mechanical strengths or higher reactivity with electrode compared with the YSZ electrolysis cells, which make it difficult to choose compatible materials, remain major challenges. In this field, SOECs have attracted a great attention in the last few years, as they offer significant power and higher efficiencies compared to conventional YSZ based electrolysers. Herein, SOECs using LSGM based electrolyte, their applications, high performance, and their issues will be reviewed.


2021 ◽  
Vol 5 (1) ◽  
pp. 67
Author(s):  
Roar Jensen ◽  
Casper van der Eijk ◽  
Aud N. Wærnes

Hydrogen will presumably become an important substitute for carbon as a reductant in the metallurgical industry for processes such as steel production. However, the challenge to supply enough CO2-free hydrogen for metallurgical processes has not been resolved yet. This paper reviews different production technologies for hydrogen and their advantages and drawbacks. Additionally, it will highlight the development of plasma technology to produce hydrogen and carbon black which has been taking place at SINTEF during the last 30 years.


2021 ◽  
Author(s):  
M. Pinzón ◽  
A. Romero ◽  
A. de Lucas-Consuegra ◽  
A.R. de la Osa ◽  
P. Sánchez

2021 ◽  
pp. 103547
Author(s):  
Seetharamulu Podila ◽  
Hafedh Driss ◽  
Arshid M. Ali ◽  
Abdulrahim A. Al-Zahrani ◽  
Muhammad A. Daous

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