scholarly journals Catalyst design strategies towards highly shape-selective HZSM-5 for para-xylene through toluene alkylation

2020 ◽  
Author(s):  
Xin Huang ◽  
Ruizhuang Wang ◽  
Xu Pan ◽  
Chuanfu Wang ◽  
Maohong Fan ◽  
...  
Keyword(s):  
Catalyst Design ◽  
Design Strategies ◽  
Toluene Alkylation ◽  
Para Xylene ◽  
Shape Selective

Towards a Design of Active Oxygen Evolution Catalysts: Insights from Automated Density Functional Theory Calculations and Machine Learning

2019 ◽  
Author(s):  
Seoin Back ◽  
Kevin Tran ◽  
Zachary Ulissi
Keyword(s):  
Machine Learning ◽  
Oxygen Evolution ◽  
Active Sites ◽  
Density Functional ◽  
Chemical Space ◽  
Density Functional Theory Calculations ◽  
Catalyst Design ◽  
Transition Metal Catalysts ◽  
Oxide Materials ◽  
Design Strategies

<div> <div> <div> <div><p>Developing active and stable oxygen evolution catalysts is a key to enabling various future energy technologies and the state-of-the-art catalyst is Ir-containing oxide materials. Understanding oxygen chemistry on oxide materials is significantly more complicated than studying transition metal catalysts for two reasons: the most stable surface coverage under reaction conditions is extremely important but difficult to understand without many detailed calculations, and there are many possible active sites and configurations on O* or OH* covered surfaces. We have developed an automated and high-throughput approach to solve this problem and predict OER overpotentials for arbitrary oxide surfaces. We demonstrate this for a number of previously-unstudied IrO2 and IrO3 polymorphs and their facets. We discovered that low index surfaces of IrO2 other than rutile (110) are more active than the most stable rutile (110), and we identified promising active sites of IrO2 and IrO3 that outperform rutile (110) by 0.2 V in theoretical overpotential. Based on findings from DFT calculations, we pro- vide catalyst design strategies to improve catalytic activity of Ir based catalysts and demonstrate a machine learning model capable of predicting surface coverages and site activity. This work highlights the importance of investigating unexplored chemical space to design promising catalysts.<br></p></div></div></div></div><div><div><div> </div> </div> </div>

scholarly journals Quasi-graphitic carbon shell-induced Cu confinement promotes electrocatalytic CO2 reduction toward C2+ products

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ji-Yong Kim ◽  
Deokgi Hong ◽  
Jae-Chan Lee ◽  
Hyoung Gyun Kim ◽  
Sungwoo Lee ◽  
...  
Keyword(s):  
High Efficiency ◽  
Co2 Reduction ◽  
Value Added ◽  
Material Design ◽  
Catalyst System ◽  
Critical Issue ◽  
Reduction Reaction ◽  
Catalyst Design ◽  
Design Strategies ◽  
Faradaic Efficiency

AbstractFor steady electroconversion to value-added chemical products with high efficiency, electrocatalyst reconstruction during electrochemical reactions is a critical issue in catalyst design strategies. Here, we report a reconstruction-immunized catalyst system in which Cu nanoparticles are protected by a quasi-graphitic C shell. This C shell epitaxially grew on Cu with quasi-graphitic bonding via a gas–solid reaction governed by the CO (g) - CO2 (g) - C (s) equilibrium. The quasi-graphitic C shell-coated Cu was stable during the CO2 reduction reaction and provided a platform for rational material design. C2+ product selectivity could be additionally improved by doping p-block elements. These elements modulated the electronic structure of the Cu surface and its binding properties, which can affect the intermediate binding and CO dimerization barrier. B-modified Cu attained a 68.1% Faradaic efficiency for C2H4 at −0.55 V (vs RHE) and a C2H4 cathodic power conversion efficiency of 44.0%. In the case of N-modified Cu, an improved C2+ selectivity of 82.3% at a partial current density of 329.2 mA/cm2 was acquired. Quasi-graphitic C shells, which enable surface stabilization and inner element doping, can realize stable CO2-to-C2H4 conversion over 180 h and allow practical application of electrocatalysts for renewable energy conversion.

Catalyst design strategies for aqueous N2 electroreduction

2021 ◽  
Vol 25 ◽  
pp. 101184
Author(s):  
Joel P. Mills ◽  
Cheng Du ◽  
Zuolong Chen ◽  
Tao Guo ◽  
Yimin A. Wu
Keyword(s):  
Catalyst Design ◽  
Design Strategies

Ultradeep Hydrodesulfurization of Diesel: Mechanisms, Catalyst Design Strategies, and Challenges

2020 ◽  
Vol 59 (49) ◽  
pp. 21261-21274
Author(s):  
Xiaoyi Weng ◽  
Liyuan Cao ◽  
Guohao Zhang ◽  
Feng Chen ◽  
Liang Zhao ◽  
...  
Keyword(s):  
Catalyst Design ◽  
Design Strategies

scholarly journals Maximizing sinusoidal channels of HZSM-5 for high shape-selectivity to p-xylene

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Chuanfu Wang ◽  
Lei Zhang ◽  
Xin Huang ◽  
Yufei Zhu ◽  
Gang (Kevin) Li ◽  
...  
Keyword(s):  
High Activity ◽  
Chemical Industry ◽  
Chemical Separation ◽  
Shape Selectivity ◽  
Toluene Alkylation ◽  
Shape Selective ◽  
Toluene Methylation ◽  
Selective Catalysis ◽  
The Cost ◽  
Very High

Abstract The shape-selective catalysis enabled by zeolite micropore’s molecular-sized sieving is an efficient way to reduce the cost of chemical separation in the chemical industry. Although well studied since its discovery, HZSM-5′s shape-selective capability has never been fully exploited due to the co-existence of its different-sized straight channels and sinusoidal channels, which makes the shape-selective p-xylene production from toluene alkylation with the least m-xylene and o-xylene continue to be one of the few industrial challenges in the chemical industry. Rather than modifications which promote zeolite shape-selectivity at the cost of stability and reactivity loss, here inverse Al zoned HZSM-5 with sinusoidal channels predominantly opened to their external surfaces is constructed to maximize the shape-selectivity of HZSM-5 sinusoidal channels and reach > 99 % p-xylene selectivity, while keeping a very high activity and good stability ( > 220 h) in toluene methylation reactions. The strategy shows good prospects for shape-selective control of molecules with tiny differences in size.

scholarly journals Roads Less Traveled: Nitrogen Reduction Reaction (NRR) Catalyst Design Strategies for Improved Selectivity

2021 ◽  
pp. 100723
Author(s):  
Bianca M. Ceballos ◽  
Ghanshyam Pilania ◽  
Kannan P. Ramaiyan ◽  
Amitava Banerjee ◽  
Cortney Kreller ◽  
...  
Keyword(s):  
Reduction Reaction ◽  
Catalyst Design ◽  
Design Strategies ◽  
Nitrogen Reduction

Catalyst design strategies for stable electrochemical CO2 reduction reaction

2020 ◽  
Vol 8 (31) ◽  
pp. 15341-15357 ◽  
Author(s):  
Woong Choi ◽  
Da Hye Won ◽  
Yun Jeong Hwang
Keyword(s):  
Co2 Reduction ◽  
Reduction Reaction ◽  
Catalyst Design ◽  
Electrochemical Activation ◽  
Impurity Effect ◽  
Design Strategies ◽  
Metal Impurity ◽  
Practical Applications ◽  
Electrochemical Co2 Reduction ◽  
Co2 Reduction Reaction

For practical applications, the deactivation processes of electrocatalysts in electrochemical CO2 reduction reactions have to be addressed by studying recent advances such as exclusion of metal impurity effect, periodic electrochemical activation and active nanocatalyst design.

Para-Xylene Maximization. Part VIII: Promotion of H-ZSM-5 Zeolite by Pt and HF Doping for Use as Catalysts in Toluene Alkylation with Methanol

2010 ◽  
Vol 31 (9-10) ◽  
pp. 1209-1216 ◽  
Author(s):  
Ahmed K. ABOUL-GHEIT ◽  
Ateyya A. ABOUL-ENEIN ◽  
Ahmed E. AWADALLAH ◽  
Salwa A. GHONEIM ◽  
Eman A. EMAM
Keyword(s):  
Toluene Alkylation ◽  
Para Xylene
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