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1.
Prev Med Rep ; 39: 102658, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38380385

ABSTRACT

Objectives: To describe the social drivers of health and health status of Native Hawaiian and Pacific Islander (NHPI) youth in the US. Methods: This is a cross-sectional analysis of the 2014 NHPI National Health Interview Survey (NHIS) which surveyed about 3,000 NHPI households, including 1,428 NHPI youth (884 0-12 yo, 421 13-17 yo, and 123 18-21 yo). We described domains of social drivers of health (SDoH), health conditions, and associations of income and food insecurity with body mass index (BMI) for NHPI youth. Results: NHPI youth come from households with a wide range in income. Approximately 20% of the cohort were food insecure. Among 18-21 yo, 10% report chronic medical conditions (5% with prediabetes). 33% of 13-17 yo and 52% of 18-21 yo were overweight/ obese. For 13-17 yo, lower income was associated with higher BMI. There was no association between food insecurity and BMI for any age group. Conclusions: Overweight/ obesity are highly prevalent among NHPI youth which is concerning for development of diabetes, hypertension, cardiovascular and kidney disease. Health efforts should focus on SDoH, obesity prevention and management for NHPI youth.

2.
Article in English | MEDLINE | ID: mdl-36231282

ABSTRACT

While the incidence and prevalence of type 2 diabetes is higher among Latino/as, Latino men are disproportionately affected and have poorer outcomes. We aimed to determine whether gender impacted any outcomes in a culturally tailored type 2 diabetes (T2D) intervention and to evaluate the effects of gender and intervention participation intensity on outcomes at 6-month follow-up. Nested path and regression models were compared with the likelihood ratio test and information criteria in a sample of Latino/a adults with T2D (n = 222) participating in a T2D community health worker (CHW)-led intervention. Path analysis showed that the effect of the intervention did not vary by gender. The intervention was associated with significant improvements in knowledge of T2D management 0.24 (0.10); p = 0.014, diabetes distress, -0.26 (0.12); p = 0.023, and self-efficacy, 0.61 (0.21); p = 0.005. At 6-month follow-up, improved self-management was associated with greater self-efficacy and Hemoglobin A1c (HbA1c) was lower by -0.18 (0.08); p = 0.021 for each unit of self-management behavior. Linear regressions showed that class attendance and home visits contributed to positive intervention results, while gender was non-significant. Pathways of change in a CHW-led culturally tailored T2D intervention can have a significant effect on participant behaviors and health status outcomes, regardless of gender.


Subject(s)
Diabetes Mellitus, Type 2 , Community Health Workers , Diabetes Mellitus, Type 2/therapy , Glycated Hemoglobin/analysis , Hispanic or Latino , Humans , Linear Models
3.
Health Equity ; 6(1): 564-573, 2022.
Article in English | MEDLINE | ID: mdl-36081882

ABSTRACT

Introduction: Pasifika (Native Hawaiian and Pacific Islander) people living in the United States experience health, economic, and social inequities, and a disproportionate burden of COVID-19 cases and deaths. This study examines employment among Pasifika living in the 10 US states with the largest Pasifika populations during the COVID-19 pandemic. Methods: We use the Current Population Survey to examine racial differences in employment status, paid work from home (PWFH), and industry telework friendliness. We use data from the Washington Office of Fiscal Management and the Washington State (WA) Employment Security Department to examine county-level unemployment claims. Results: Nationally, Pasifika did not self-report unemployment significantly more than Black, Latino, Asian, and American Indian/Alaska Native respondents, but in WA counties with high Pasifika concentrations, unemployment insurance claim rates were higher compared with all other racial groups, particularly Whites and Asians. Surprisingly, Pasifika had more PWFH opportunities, but worked in less telework-friendly industries nationally. Discussion: This study demonstrates the complexity of employment among Pasifika during the COVID-19 pandemic. The findings correspond with national reports of racialized communities impacted by unemployment, including Pasifika. Marginally significant differences in unemployment nationally may be due to Pasifika working largely in essential industries requiring workplace attendance. Health Equity Implications: Although overlooked or overshadowed by size, our findings highlight the need for continued advocacy to support data disaggregation and Pasifika data sovereignty. This can be achieved through collaborations between researchers as well as local and community organizations to address data needs of Pasifika communities.

4.
Patient Educ Couns ; 105(7): 2166-2173, 2022 07.
Article in English | MEDLINE | ID: mdl-34903389

ABSTRACT

OBJECTIVE: To examine which components of a culturally tailored community health worker (CHW) intervention improved glycemic control and intermediate outcomes among Latina/o and African American participants with diabetes. METHODS: The sample included 326 African American and Latina/o adults with type 2 diabetes in Detroit, MI. CHWs provided interactive group diabetes self-management classes and home visits, and accompanied clients to a clinic visit during the 6-month intervention period. We used path analysis to model the processes by which each intervention component affected change in diabetes self-efficacy, diabetes-related distress, knowledge of diabetes management, and HbA1c. RESULTS: The group-based healthy lifestyle component was significantly associated with improved knowledge. The group-based self-management section was significantly associated with reduced diabetes-related distress. Intervention class attendance was positively associated with self-efficacy. Diabetes self-management mediated the reductions in HbA1c associated with reductions in diabetes distress. CONCLUSIONS: Path analysis allowed each potential pathway of change in the intervention to be simultaneously analyzed to identify which aspects of the CHW intervention contributed to changes in diabetes-related behaviors and outcomes among African Americans and Latinas/os. PRACTICE IMPLICATIONS: Findings reinforce the importance of interactive group sessions in efforts to improve diabetes management and outcomes among Latina/o and African American adults with diabetes.


Subject(s)
Community Health Workers , Diabetes Mellitus, Type 2 , Adult , Black or African American , Diabetes Mellitus, Type 2/therapy , Glycated Hemoglobin/analysis , Hispanic or Latino , Humans , Self Care
5.
Sci Adv ; 7(49): eabj7667, 2021 Dec 03.
Article in English | MEDLINE | ID: mdl-34851673

ABSTRACT

Spin-orbit coupling (SOC) is responsible for a range of spintronic and topological processes in condensed matter. Here, we show photonic analogs of SOCs in exciton-polaritons and their condensates in microcavities composed of birefringent lead halide perovskite single crystals. The presence of crystalline anisotropy coupled with splitting in the optical cavity of the transverse electric and transverse magnetic modes gives rise to a non-Abelian gauge field, which can be described by the Rashba-Dresselhaus Hamiltonian near the degenerate points of the two polarization modes. With increasing density, the exciton-polaritons with pseudospin textures undergo phase transitions to competing condensates with orthogonal polarizations. Unlike their pure photonic counterparts, these exciton-polaritons and condensates inherit nonlinearity from their excitonic components and may serve as quantum simulators of many-body SOC processes.

6.
Sch Psychol ; 36(6): 546-554, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34766816

ABSTRACT

As schools physically closed across the country to protect against the spread of the COVID-19 pandemic, it became clear early on that the burden on students will not be equally shared. Structural racism patterns the lives of people of color that, in turn, increases their exposure to the effects of the pandemic further impacting the quality of education the students of color have access to. It is critical to examine the ways in which racial disparities in social emotional and educational outcomes have the potential to increase as a result of the pandemic. To that end, using a content analysis of an open-ended survey, this study examines (a) how teachers and school staff experienced the pandemic, (b) their perception of student experiences during the transition to remote learning, and (c) school staff's perceptions of how racial inequities may be increased as a result of the pandemic. Our findings highlight the deep, but unequal impact of the pandemic on school staff, students, and their families. Teachers are overwhelmed and overworked, struggling to manage multiple roles while working at home. They also have tremendous empathy for the weight of the losses that students have experienced, and concern for the well-being of students in difficult living or family situations. However, most school staff maintained a colorblind analysis of the way the pandemic is affecting their students and did not recognize the role of systemic racism or potential for racial disparities to be increased. Implications and limitations are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Subject(s)
COVID-19 , Pandemics , Humans , Perception , SARS-CoV-2 , Schools
7.
Diabetes Care ; 44(5): 1108-1115, 2021 05.
Article in English | MEDLINE | ID: mdl-33958424

ABSTRACT

OBJECTIVE: To simulate the long-term cost-effectiveness of a peer leader (PL)-led diabetes self-management support (DSMS) program following a structured community health worker (CHW)-led diabetes self-management education (DSME) program in reducing risks of complications in people with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: The trial randomized 222 Latino adults with T2D to 1) enhanced usual care (EUC); 2) a CHW-led, 6-month DSME program and 6 months of CHW-delivered monthly telephone outreach (CHW only); or 3) a CHW-led, 6-month DSME program and 12 months of PL-delivered weekly group sessions with telephone outreach to those unable to attend (CHW + PL). Empirical data from the trial and the validated Michigan Model for Diabetes were used to estimate cost and health outcomes over a 20-year time horizon from a health care sector perspective, discounting both costs and benefits at 3% annually. The primary outcome measure was the incremental cost-effectiveness ratio (ICER). RESULTS: Over 20 years, the CHW + PL intervention had an ICER of $28,800 and $5,900 per quality-adjusted life-year (QALY) gained compared with the EUC and CHW-only interventions, respectively. The CHW-only intervention had an ICER of $430,600 per QALY gained compared with the EUC intervention. In sensitivity analyses, the results comparing the CHW + PL with EUC and CHW-only interventions were robust to changes in intervention effects and costs. CONCLUSIONS: The CHW + PL-led DSME/DSMS intervention improved health and provided good value compared with the EUC intervention. The 6-month CHW-led DSME intervention without further postintervention CHW support was not cost effective in Latino adults with T2D.


Subject(s)
Diabetes Mellitus, Type 2 , Self-Management , Community Health Workers , Cost-Benefit Analysis , Diabetes Mellitus, Type 2/therapy , Humans , Public Health
9.
Hum Biol ; 92(1): 45-57, 2020 11 17.
Article in English | MEDLINE | ID: mdl-33231026

ABSTRACT

Native Hawaiian and other Pacific Islanders, and the environment they are in relationship with, have been the targets of exploitation, extraction, and destruction. Environmental atrocities throughout the Pacific have demonstrated how imperialism, capitalism, and white supremacy drive destruction through efforts to dominate and exploit for material gain. The relationship between Pacific people and the environment, which defines who they are socially, spiritually, and ancestrally, continues to be damaged and even severed by these injustices. The purpose of this article is to provide examples of major environmental injustices in the Pacific and to develop a deeper understanding of the relationship between settler colonialism and environmental injustices. Indigenous knowledge, with a focus on traditional ecological knowledge, is incorporated not just to demonstrate the deep impact of injustices on Pacific people's cultures but also to highlight how this way of knowing cultivates a path to revitalization and community resilience. Cultural practices rooted in traditional ecological knowledge, such as the preservation of food systems, promote reciprocity between living beings and self-determination, necessary for community flourishing. With this understanding, Pacific peoples' relationship with their land offers further evidence of the critical role culture and Indigenous knowledge can play in environmental justice policies and practices.


Subject(s)
Colonialism , Native Hawaiian or Other Pacific Islander , Hawaii , Humans , White People
10.
Health Educ Behav ; 47(1): 47-56, 2020 02.
Article in English | MEDLINE | ID: mdl-31933395

ABSTRACT

Background. Community health workers (CHWs), often called "health promotion volunteers" in Japan, are individuals who act as a natural helping resource in the community. Aim. This study tested the efficacy of a CHW-based intervention to improve dietary habits among community-dwelling older people in Japan, using a controlled, crossover design. Method. Seventy-eight people aged 65 to 74 years with poor dietary variety living in four administrative districts in Hikone City (Shiga Prefecture, Japan) were nonrandomly allocated to an immediate-intervened group (IIG; n = 41) or a delayed-intervened group (DIG; n = 37). Participants joined a biweekly, four-session program (120 minutes/session), comprising "CHW drama-style lectures," "group discussion among participants and CHWs," "tasting of dishes," and "take-home practical activities." For the initial 2-month period, the IIG received the intervention and the DIG did not. The groups were crossed over for the subsequent 2-month period. The primary outcome measure was participants' dietary variety score (score range: 0-10). Results. The dietary variety score in the IIG significantly increased in the initial 2-month period compared with the DIG (effect size 1.60 points; 95% confidence interval: 0.75, 2.45). The intervention had a similar effect in the DIG in the subsequent 2-month period. Moreover, an analysis within the IIG showed that the intervention effects persisted for at least 2 months after the intervention. Conclusions. The CHW-based intervention improved dietary habits among older people. Our findings provide evidence that a CHW-based natural helping approach is a possible solution to promote healthy aging in the community.


Subject(s)
Community Health Workers , Feeding Behavior , Health Promotion , Independent Living , Aged , Community Health Services , Cross-Over Studies , Female , Humans , Japan , Male
11.
J Ethn Cult Divers Soc Work ; 30(1-2): 1-12, 2020.
Article in English | MEDLINE | ID: mdl-34135696

ABSTRACT

This special issue and introduction focuses on promoting health equity and addressing health disparities among Indigenous peoples of the United States (U.S.) and associated Territories in the Pacific Islands and Caribbean. We provide an overview of the current state of health equity across social, physical, and mental health domains. In Part 1 of the special issue, we trace promotive, protective, and risk factors related to Indigenous health equity. Part 2 of the special issue describes interventions that address and promote wellness, providing promising pathways to achieving and transcending health equity.

12.
Acc Chem Res ; 52(10): 2950-2959, 2019 Oct 15.
Article in English | MEDLINE | ID: mdl-31571486

ABSTRACT

Lead halide perovskites (LHPs) are attractive material systems for light emission, thanks to the ease and diverse routes of synthesis, the broad tunability in color, the high emission quantum efficiencies, and the strong light-matter coupling which may potentially lead to exciton-polariton condensation. This account contrasts the laser-like coherent light emission from highly lossy Fabry-Perot cavities, formed naturally from LHP nanowires (NWs) and nanoplates (NPs), with highly reflective cavities made of LHP gain media, sandwiched between two distributed Bragg reflector (DBR) mirrors. The mechanism responsible for the operation of conventional semiconductor lasers involves stimulated emission of electron and hole pairs bound by the Coulomb potential, i.e., excitons or, at excitation density above the so-called Mott threshold, an electron-hole plasma (EHP). We discuss how lasing from LHP NWs or NPs likely originates from stimulated emission of an EHP, not excitons or exciton-polaritons. A character central to this kind of lasing is the dynamically changing photonic properties in the naturally formed cavity. In contrast to the more static conditions of a DBR cavity, lasing modes and gain profiles are extremely sensitive to material properties and excitation conditions in an NW/NP cavity. While such unstable photonic cavities pose engineering challenges in the application of NW/NP lasers, they provide excellent probes of many-body physics in the LHP material. For sufficiently strong light-matter coupling expected for LHPs in DBR cavities, an exciton-polariton, i.e., the superposition state between the exciton and the cavity photon, can form. An exciting prospect of strong light-matter coupling is the potential formation of an exciton polariton condensate, which possesses many interesting quantum and nonlinear effects, such as superfluidity, long-range coherence, and laserlike light emission. However, it is difficult to distinguish coherent light from an exciton-polariton condensate and that from conventional stimulated laser emission. Several reports have established the condition of strong coupling for LHPs in DBR cavities. We stress, however, that these studies have not included necessary experiments to unambiguously establish the formation of exciton-polariton condensation, and several experiments and routes of analysis are needed to make a more convincing case for exciton-polariton condensation in LHP based systems. The potential of exciton-polariton condensation expands the horizon of LHP materials from conventional optoelectronics to quantum devices.

13.
J Am Chem Soc ; 141(33): 13143-13147, 2019 08 21.
Article in English | MEDLINE | ID: mdl-31357860

ABSTRACT

Singlet fission, the generation of two triplet excited states from the absorption of a single photon, may potentially increase solar energy conversion efficiency. A major roadblock in realizing this potential is the limited number of molecules available with high singlet fission yields and sufficient chemical stability. Here, we demonstrate a strategy for developing singlet fission materials in which we start with a stable molecular platform and use strain to tune the singlet and triplet energies. Using perylene diimide as a model system, we tune the singlet fission energetics from endoergic to exoergic or iso-energetic by straining the molecular backbone. The result is an increase in the singlet fission rate by 2 orders of magnitude. This demonstration opens a door to greatly expanding the molecular toolbox for singlet fission.

14.
Am J Community Psychol ; 64(1-2): 107-117, 2019 09.
Article in English | MEDLINE | ID: mdl-31322733

ABSTRACT

Although Hawai'i is often portrayed as an idyllic paradise and is recognized as one of the healthiest States in the United States, pervasive health disparities exist among Native Hawaiians. Similar to other indigenous populations across the globe, these disparities are linked to unjust social and economic policies rooted in colonization and historical trauma. Western-centric efforts to address these disparities have yielded limited results. Consequently, indigenous frameworks to decolonize western-centric research processes have emerged. The Waimanalo Pono Research Hui is an example of a community-academic partnership that uses indigenous methodologies and principles of community-based participatory research as the foundation to engage Native Hawaiian community members in research. Monthly gatherings are held where community members and academic researchers share a meal and discuss community priorities with the goal of shaping research and programming that are rooted in Native Hawaiian values. A mission for the group has been created as well as protocols for community engagement to ensure all projects that work with the Waimanalo Pono Research Hui are ethically sound and grounded in the community's preferences, cultural knowledge, and lived experiences. Our community members continually report that the Waimanalo Pono Research Hui has positively transformed their perception of and willingness to engage in research. Similarly, university students and academic researchers express how much their knowledge about working with communities has grown and inspired them. Creating spaces for communities and researchers to build authentic relationships and engage in ongoing conversations can promote culturally grounded and community-driven research and programming.


Subject(s)
Community-Based Participatory Research/methods , Community-Institutional Relations , Cultural Competency , Health Promotion/methods , Indigenous Peoples , Community-Based Participatory Research/organization & administration , Culture , Hawaii , Health Promotion/organization & administration , Humans
15.
Glob Health Promot ; 26(3_suppl): 87-92, 2019 04.
Article in English | MEDLINE | ID: mdl-30964410

ABSTRACT

Prior to western arrival in 1778, Native Hawaiians possessed a sophisticated culture and resource management system conducive to an island ecosystem. However, disenfranchisement from ancestral lands and traditional food sources as a result of colonization led to Native Hawaiians being forced to abandon many of their traditional practices. Today, many Native Hawaiians experience food insecurity, placing them at further risk for obesity and other nutrition-related chronic diseases. Consequently, there is a growing need for place-based and culturally relevant strategies rooted in Hawaiian epistemology to address these issues. This paper describes the history and development of one such intervention - the MALAMA study - in the community of Waimanalo that innovatively merges the modern technology of aquaponics with traditional Native Hawaiian practices and values.


Subject(s)
Aquaculture/methods , Cultural Characteristics , Hydroponics/methods , Native Hawaiian or Other Pacific Islander , Ecosystem , Food Supply , Hawaii , Humans
16.
Nat Commun ; 10(1): 265, 2019 01 16.
Article in English | MEDLINE | ID: mdl-30651537

ABSTRACT

Lead halide perovskites are emerging as an excellent material platform for optoelectronic processes. There have been extensive discussions on lasing, polariton formation, and nonlinear processes in this material system, but the underlying mechanism remains unknown. Here we probe lasing from CsPbBr3 perovskite nanowires with picosecond (ps) time resolution and show that lasing originates from stimulated emission of an electron-hole plasma. We observe an anomalous blue-shifting of the lasing gain profile with time up to 25 ps, and assign this as a signature for lasing involving plasmon emission. The time domain view provides an ultra-sensitive probe of many-body physics which was obscured in previous time-integrated measurements of lasing from lead halide perovskite nanowires.

17.
Geriatrics (Basel) ; 3(3)2018 09.
Article in English | MEDLINE | ID: mdl-30345345

ABSTRACT

Diabetes management for older Latino adults is complex, given a higher incidence of multiple coexisting medical conditions and psychosocial barriers to self-management. Community health workers (CHWs) may be effective in reducing these barriers. The REACH Detroit CHW randomized controlled intervention studies with Latino/as with diabetes found improvements in self-management behaviors and glucose control after participating in a CHW-led intervention. Using data from the REACH Detroit Partnership's cohort 3, this study used descriptive statistics and multiple linear regression analyses to evaluate whether the six-month CHW intervention had a greater effect on older Latino/as (ages 55 and older) than younger participants between baseline and post-intervention follow-up at six months. There were significant intervention effects by age group that varied by outcome. Compared to a control group that received enhanced usual care, there were statistically significant intervention effects demonstrating greater self-efficacy scores 1.27 (0.23, 2.32); p < 0.05, and reductions in HbA1c 1.02 (-1.96,-0.07); p < 0.05, among older participants in the CHW intervention, and increases in diabetes support 0.74 (0.34, 1.13); p < 0.001; and understanding of diabetes management 0.39 (0.08, 0.70); p < 0.01 among younger participants.

18.
Diabetes Care ; 41(7): 1414-1422, 2018 07.
Article in English | MEDLINE | ID: mdl-29703724

ABSTRACT

OBJECTIVE: This study evaluated the effectiveness of a community health worker (CHW) diabetes self-management education (DSME) program, followed by two different approaches to maintain improvements in HbA1c and other clinical and patient-centered outcomes over 18 months. RESEARCH DESIGN AND METHODS: The study randomized 222 Latino adults with type 2 diabetes and poor glycemic control from a federally qualified health center to 1) a CHW-led, 6-month DSME program or 2) enhanced usual care (EUC). After the 6-month program, participants randomized to the CHW-led DSME were further randomized to 1) 12 months of CHW-delivered monthly telephone outreach (CHW-only) or 2) 12 months of weekly group sessions delivered by peer leaders (PLs) with telephone outreach to those unable to attend (CHW+PL). The primary outcome was HbA1c. Secondary outcomes were blood pressure, lipid levels, diabetes distress, depressive symptoms, understanding of diabetes self-management, and diabetes social support. Assessments were conducted at baseline and at 6, 12, and 18 months. RESULTS: Participants in the CHW intervention at the 6-month follow-up had greater decreases in HbA1c (-0.45% [95% CI -0.87, -0.03]; P < 0.05) and in diabetes distress (-0.3 points [95% CI -0.6, -0.03]; P < 0.05) compared with EUC. CHW+PL participants maintained HbA1c improvements at 12 and 18 months, and CHW-only participants maintained improvements in diabetes distress at 12 and 18 months. CHW+PL participants also had significantly fewer depressive symptoms at 18 months compared with EUC (-2.2 points [95% CI -4.1, -0.3]; P < 0.05). Participants in CHW-led DSME had significant improvements in diabetes social support and in understanding of diabetes self-management at 6 months relative to EUC, but these intervention effects were not sustained at 18 months. CONCLUSIONS: This study demonstrates the effectiveness of a 6-month CHW intervention on key diabetes outcomes and of a volunteer PL program in sustaining key achieved gains. These are scalable models for health care centers in low-resource settings for achieving and maintaining improvements in key diabetes outcomes.


Subject(s)
Community Health Workers , Diabetes Mellitus, Type 2/therapy , Hispanic or Latino , Leadership , Peer Group , Self-Management/methods , Adult , Aged , Community Health Workers/organization & administration , Diabetes Mellitus, Type 2/ethnology , Female , Follow-Up Studies , Glycated Hemoglobin/analysis , Health Education/methods , Health Education/organization & administration , Humans , Male , Middle Aged , Outcome Assessment, Health Care , Patient Participation/methods , Self Care/methods , Treatment Outcome
19.
ChemCatChem ; 9(9): 1621-1631, 2017 05 10.
Article in English | MEDLINE | ID: mdl-28706569

ABSTRACT

A series of copper-zinc acetate and zincian georgeite precursors have been produced by supercritical CO2 antisolvent (SAS) precipitation as precursors to Cu/ZnO catalysts for the water gas shift (WGS) reaction. The amorphous materials were prepared by varying the water/ethanol volumetric ratio in the initial metal acetate solutions. Water addition promoted georgeite formation at the expense of mixed metal acetates, which are formed in the absence of the water co-solvent. Optimum SAS precipitation occurs without water to give high surface areas, whereas high water content gives inferior surface areas and copper-zinc segregation. Calcination of the acetates is exothermic, producing a mixture of metal oxides with high crystallinity. However, thermal decomposition of zincian georgeite resulted in highly dispersed CuO and ZnO crystallites with poor structural order. The georgeite-derived catalysts give superior WGS performance to the acetate-derived catalysts, which is attributed to enhanced copper-zinc interactions that originate from the precursor.

20.
Chem Sci ; 8(3): 2436-2447, 2017 Mar 01.
Article in English | MEDLINE | ID: mdl-28451351

ABSTRACT

Zincian georgeite, an amorphous copper-zinc hydroxycarbonate, has been prepared by co-precipitation using acetate salts and ammonium carbonate. Incorporation of zinc into the georgeite phase and mild ageing conditions inhibits crystallisation into zincian malachite or aurichalcite. This zincian georgeite precursor was used to prepare a Cu/ZnO catalyst, which exhibits a superior performance to a zincian malachite derived catalyst for methanol synthesis and the low temperature water-gas shift (LTS) reaction. Furthermore, the enhanced LTS activity and stability in comparison to that of a commercial Cu/ZnO/Al2O3 catalyst, indicates that the addition of alumina as a stabiliser may not be required for the zincian georgeite derived Cu/ZnO catalyst. The enhanced performance is partly attributed to the exclusion of alkali metals from the synthesis procedure, which are known to act as catalyst poisons. The effect of residual sodium on the microstructural properties of the catalyst precursor was investigated further from preparations using sodium carbonate.

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