The goal-gradient hypothesis denotes the classic finding from behaviorism that animals expend more effort as they approach a reward. Building on this hypothesis, the authors generate new propositions for the human psychology of rewards. They test these propositions using field experiments, secondary customer data, paper-and-pencil problems, and Tobit and logit models. The key findings indicate that (1) participants in a real café reward program purchase coffee more frequently the closer they are to earning a free coffee; (2) Internet users who rate songs in return for reward certificates visit the rating Web site more often, rate more songs per visit, and persist longer in the rating effort as they approach the reward goal; (3) the illusion of progress toward the goal induces purchase acceleration (e.g., customers who receive a 12-stamp coffee card with 2 preexisting "bonus" stamps complete the 10 required purchases faster than customers who receive a "regular" 10-stamp card); and (4) a stronger tendency to accelerate toward the goal predicts greater retention and faster reengagement in the program. The conceptualization and empirical findings are captured by a parsimonious goaldistance model, in which effort investment is a function of the proportion of original distance remaining to the goal. In addition, using statistical and experimental controls, the authors rule out alternative explanations for the observed goal gradients. They discuss the theoretical significance of their findings and the managerial implications for incentive systems, promotions, and customer retention.

The authors propose that people use 2 routes in justifying self-gratification: 1st through hard work or excellence (entitlement) and the 2nd through the attainment of vices without depleting income. This framework was tested using real tasks and choices adopted from prior research on self-control. The results indicate that (a) higher effort and (bogus) excellence feedback increase preferences for vice rewards, but these effects are reversed or attenuated when the interchangeability of effort and income is implied; (b) willingness to pay in effort is greater for vices than virtues, but willingness to pay in income is higher for virtues; and (c) these effects are magnified among individuals with stronger (chronic or manipulated) guilt. The authors discuss the ability of the justification routes to explain the findings of prior self-control research.

Because it is harder to justify hedonic purchases than utilitarian purchases, it is proposed that promotions will have a stronger positive effect on the purchase likelihood of hedonic than utilitarian products. This and related propositions are tested in multiple studies using a variety of product categories and promotions. The results demonstrate that promotions are more effective in driving purchase decisions when: (a) the product is hedonic rather than utilitarian; (b) the product is framed as more hedonic; and (c) the consumer has a hedonic rather than utilitarian consumption goal. Consistent with our conceptualization, the enhanced impact of promotions on hedonic purchases is attenuated when: (a) the hedonic product is intended as a gift for others; (b) consumers can construct justifications for their purchase ahead of time; (c) consumers are not accountable for their decisions; and (d) the promotion is contingent on purchasing additional product units (i.e., a quantity discount like “Buy 10, get 50% off”). Importantly, the present research reconciles and explains the seemingly inconsistent prior findings regarding the effects of price versus quantity promotions.

Stearate-pillared layered double hydroxide (LDH) promoted by K 2 CO 3 as a precursor for pre-combustion of a CO 2 adsorbent is presented for the first time. This novel precursor is synthesized from commercial hydrotalcite, one kind of LDH, undergoing acid-aid anionic exchange and wet impregnation processes. The pillared stearate expands the gallery height from 0.28 nm for carbonate-intercalated LDH (almost the diameter of the K ion, 0.276 nm) to a much spatial 3.4 nm for stearate-intercalated LDH, proven by characteristic diffraction peaks in powder X-ray diffraction (PXRD). Transmission electron microscopy (TEM) micrographs and energy-dispersive X-ray spectroscopy (EDX) provide a vivid layout of K and its on-spot composition, respectively, deducing that a well-dispersed K ion promotion exists inside brucite-like layers. Experimental results carried out by a thermogravimetric analyzer (TGA) show striking CO 2 capacity up to 1.93 mmol g −1 at 300°C, 1.7 times higher than that of a conventional K 2 CO 3 -promoted hydrotalcite adsorbent (1.11 mmol g −1 ), and fast adsorption kinetics for this precursor.

Nanorod-like phosphorus-doped ordered mesoporous γ-alumina (OMA), which has abundant ordered pore channels in the nanorods, was rapidly synthesized through a modified sol–gel strategy without use of any mineral acids. Highly dispersed Pd-based catalysts were synthesized by taking as-obtained phosphorus-doped OMA materials as carriers for methane combustion. The crystallization temperature of γ-Al2O3 was increased by phosphorus doping. The surface acidity properties of γ-Al2O3 were modified upon phosphorus incorporation, which had a significant effect on catalyst activities, and this influence was much more conspicuous for the supports calcined at high temperature. The incorporation of phosphorus adjusted the distribution of palladium active species and the reducibility of catalysts, synergistically affecting the low-temperature catalytic performance. Pd/6P-OMA catalyst demonstrated enhanced low-temperature catalytic properties and stability in the 13-cycle stability and long-term stability tests. During the reaction cycles, the total CH4 conversion temperature for Pd/6P-OMA catalyst was as low as 345 °C, which could be reduced to 321 °C via hydrogen reduction treatment. In comparison with the catalyst without dopant, the Pd/6P-OMA catalyst also exhibited higher hydrothermal stability in the presence of excess water vapor in the feed.